Hey man, to respond to your question you technically don't need cardio, but it can help. The most important thing is diet, you're gonna have to cut the calories to slim down even more if that's your goal, you need to be around 10% body fat to start seeing your abs, this can be very difficult to achieve. I know some people who recommend just cutting out carbs almost completely except for leafy greens like spinach or cabbage, this will shred fat off your body but if you stay on this for more than a couple weeks its really going to start eating your muscle away. I've heard some people just like to do that(low carb) and do some lifting exercise to preserve strength, for cardio they do a brisk walk on a treadmill, enough to break a sweat but still be able to have a conversation, this will target the calories burned to be from fat.
I also know people who say HIIT is the best to get "shredded." I tend to disagree, I find it really rips off my muscle if I'm in a calorie deficit, I lean more to a mixture of a couple more moderate jogs(heart rate around 170) and then a few days with just some nice easier work like a bike or slower jog/fast walk (heart rate around 140.) In general, if you put up a calorie deficit, you'll lose weight, you can't specifically lose weight in one area, but it'll happen naturally as your body deems where. If you're already a bit slim I'd recommend going on a two week hard cut of low carbs (less than 40 grams) and then incorporating some fast walks/moderate jogs. You'll feel pretty bad with no carbs, but it's the "quickest" way to lose those last pounds on you. If you know you a decent amount to lose(more than like, 5 pounds) then I'd suggest just cutting calories and again, doing some moderate jogs.
