imstarting2moro, I wish I had better advice for you. I was vegetarian for some time, prior to going vegan, so it was already kind of second nature. When I became vegetarian, 'the Internet' was still pretty new. So, that's not a resource I used, at the time.
SINCE being vegan, I've visited a few sites, seen a few documentaries, and read a few books. However, I haven't really utilized them, in terms of following advice, or anything like that. I was already a happy vegan.
But what can I tell you...?
Don't fall for the protein myths. Pretty much everything has protein in it. You may hear others say that 'complete' proteins are important. In reality, even complete proteins you consume are broken down by the body. It just means you'll have consumed all necessary amino acids in that one food. ...Very convenient. There are several complete proteins in plant form. I typically consume soy, quinoa, hemp, salba, and spirulina. You can also combine foods, to make a complete protein in one dish. Many cultures eat 'rice & peas'/'red beans & rice', as a staple. Then, you can get ample protein in nuts, nut butters, nut milks, seeds, beans, legumes, and more.
Non-heme iron (iron from plant sources) is most fully absorbed if combined with a citrus. When I eat a spinach salad or edamame, I typically have it with grapefruit juice, to get the most iron out of it. (sometimes some orange wedges or berries in a salad). Oh, also purely for iron, a snack might be a slice of wholegrain bread smeared with blackstrap molasses (with a grapefruit juice chaser). (I should eat an actual grapefruit, but I'm lazy, in that sense. I already prepare most of my meals from scratch, which can be a bit time-consuming, at times...depending on what I'm preparing.). I try to keep iron in mind because I'm a woman...who menstruates. Your girlfriend may also want to ensure she's getting enough iron. Even meat-eating women are often iron deficient. My mother, who eats a fair bit of meat, was diagnosed with anemia at age 85. My bloodwork is always perfect.
You can look-up different nutrients for vegan sources. If I have a bowl of spinach, for example, I typically have it with some tomato, and a balsamic dressing, with a sprinkling of sesame seeds, and a few almonds, plus a glass of grapefruit juice on the side. The spinach is a good source of iron and calcium. The almonds and sesame seeds are also a good source of calcium (among other things). Almonds also have some extra protein. (Fitness experts tend to recommend always eating a protein with a complex carb, at every meal and snack. So, I try to also have something a bit higher in protein, even if I'm only planning to have a piece of fruit or a vegetable.)
I'm not a huge fan of soy, in general (except edamame and some tofu dishes). So, I use almond milk, instead of soy milk. Since I've been trying to lose weight, I haven't eaten any cereal, and that's the primary reason I buy almond milk. Thus, I haven't had much almond milk in the past few months. But, normally, it's in my fridge. (I gained weight over several years because my previously-symptom-free PCOS made me insulin resistant -IR. Since I discovered what was going on, and learned about a natural insulin sensitizer, I'm quickly getting back to my pre-IR weight. Wahoo!)
Hmmmm... ...what else?
You may hear that a vegan diet lacks B12. That's not inherently accurate, but you may need to ensure you consume fortified foods. You see, our natural diet had ample B12, either from bacteria in dirt, or in animal products. If you grow your own vegetables, and eat the skin (or otherwise get some of that beneficial, earthy bacteria into you) you SHOULD be fine. The problem is, nowadays, vegetables are washed, irradiated, and/or cleansed and packaged to within an inch of their nutritional value. That's a modern problem. (If you ever get a chance to watch a documentary entitled 'The Dirt Vaccine', do it. Aside from just the fascinating premise, you'll see evidence of a correlation between a society starting to consume primarily washed, very "clean" vegetables and a remarkable rise in autoimmune disorders. It's a smilar premise as to why children raised with pet dogs have fewer autoimmune disorders than those with no pets. In short, evidence seems to suggest the more non-lethal bacteria we're exposed to, the stronger our immune systems.) I believe the nut milks are usually fortified with B12.
I never used to like tofu, and now I really like it. Still, I only eat tofu maybe once or twice a month.
New vegans often rely too heavily on packaged, processed foods, such as those awful fake meat products. They're okay, once in a while, like a piece of cake is okay once in a while. But fake meats, and processed food in general, are not part of a healthy, vegan diet. Ideally, the bulk of your det should be made-up of whole foods. ...Foods that look pretty much the same way they grow, when you buy them.
Let's see... If you are buying processed foods, common, non-vegan ingredients are gelatin, casein (and milk, of course), lard (of course), cochineal (crushed bugs used for colouring), egg, lecithin (where the source is not specified as plant-based)... You can look-up non-vegan ingredients, on the Internet.
Any animal product is not vegan. Silk is not vegan. Wool is not vegan. Honey is not vegan.
Most dark chocolate is vegan. Just check for soy lecithin and no milk.
Actually, that brings up a common complaint from new vegans. If you insist on buying processed foods, rather than cooking from scratch, you will probably spend 50% of your time (or 100% more time) at the grocery store, reading labels. That, alone, will probably be enlightening, and inspire dietary change.
In any event, I cook MANY of my mom's tried and true recipes, by simply replacing the animal products with an alternative, or eliminating them entirely. If you like, you can use texturized vegetable protein in place of ground beef in rice and pasta dishes. Milk can be replaced with almond/soy/rice milk. Butter can be replaced with vegan margarine/spread. Just about every vegan seems to have a package of Ener-G egg replacer in their pantries, for baking.
All my local grocery stores have increasing variety of vegan processed foods...which is great, I suppose. I like to remind people that pretty much the entire produce section of the store is, and always has been, vegan.
As for junk food...
These should generally be off the menu, if you're trying to get fitter or lose weight but... There are loads of vegan treats available. Coke is vegan. Doritos 'Sweet Chili Heat' tortilla chips are vegan. There are vegan marshmallows, chocolates, candies, potato chips, etc. I have no love affair with PETA, but they do have a list of snack foods that are vegan. Do a search for "accidentally vegan".
As for supplements, here's the skinny...
The overwhelming majority of supplements are made for, and consumed by, non-vegans. Most supplements are not vegan, as they typically contain some form of animal product, even if it's just the gelatin capsule. I take a vegan cinnamon supplement for my insulin resistance, not because I'm vegan.
But, a good multi-vitamin might provide peace of mind, just as it does for meat eaters and vegetarians. I think any dietician would emphasize a balanced and complete diet, above all, so there's no need to supplement. I don't take any nutrition-related supplements.
I have purchased products with confidence from VeganEssentials.com and veganchic.com. Of course, loads of things are vegan, without trying. There are lists of fast food restaurants and the corresponding vegan eats they have available. Pizza dough is usually vegan, as is the sauce. Just order it with loads of vegetables and no cheese, and you don't have to skip pizza night. There's a lot of information out there. Just search the Internet, when a question pops into your head.
As I was writing all this, I realized I have EASILY a dozen unread vegan cookbooks. People keep giving them to me as gifts, not knowing that I hate cookbooks for some reason. I really love my food, and when I want to try something new, I just try to devise my own recipe. While I should really crack them open and try some of the recipes, I am kind of a picky eater, in the sense that there are several foods I don't like. For instance, I'm not a fan of eggplant/aubergine, zucchini/courgette, or mushrooms. Yet just tell a chef you're vegan, and you're getting a dish made-up of those things, almost guaranteed.
As for the ham sandwich dream...
My advice is generally not to label yourself. It's nobody else's business why you're choosing the foods you do. Sure, I'm here saying, "I'm vegan." But, in real life, it rarely comes up. When I get a salad at a restaurant, and ask for it without cheese or without a cream sauce, many servers have assumed I'm lactose intolerant. What do I care? They don't actually care, either. I am comfortable getting what I want in most areas of life...in a good way. But since I'm not trying to prove anything to anyone with my veganism, I don't bring it up. My husband, a meat-eater, is more likely to discuss it with others, and I'm the one changing the subject. I can't say I've met a long-time, successful vegan who doesn't view the choice as deeply personal and virtually impossible to impose on others, in any meaningful or lasting way.
So, I think I'd say that if you're just eating a vegan diet, and only doing it for health reasons, then maybe animal products aren't unethical for you. As such, if you're really craving a ham sandwich (or whatever) you should just do it. There is no vegan police. In fact, no one in an industrialized country is 100% vegan. If someone is judging you for only being 97% vegan and he/she is 98% vegan, that's obviously ridiculous. Unless you go around announcing you're vegan, anyone who judges you for what you're eating is just a jerk. If you know, in advance, you plan to continue using or consuming animal products from time to time, you might not want to tell people you're vegan. In fact, if you only plan to have a vegan diet, you should specify that. Others might be understandably confused by someone calling himself vegan, and wearing leather shoes.
I usually advise new vegans to simply choose non-animal-product meals and products whenever they choose, without labeling themselves. If it's just for this meal/product, just for today, for a month, a year, or the intent is the rest of their lives, it really does not require a label. The label is a good shortcut, for why you want something a certain way. But, over the years, I've learned it's best for me to simply get what I want because I have that right. For those who want to occasionally consume animal products, not labeling oneself allows that freedom, without others' judgement. Since I occasionally eat something vegetarian, even I would refer to myself as "mostly vegan".
Again, that's way too much information. But I hope it hels you get started.
