Simple diet phase 1 - you can google macro calculator and the first couple of links there give pretty good results for a calorie goal. This is your base to start off with. Don't worry about hitting the protein, fats, and carb goals in the beginning. Just work on hitting the same number of calories every day.
An easy way to track it is with the free MyFitnessPal app, super handy. It's also great for tracking how much sodium you eat every day which can lead to holding on to water weight.
Track you weight every day and journal it. Don't be discouraged by fluctuations from day to day. In the first 7 days, it is more important that you're getting into a routine of recording what you're eating and hitting your calorie goal (try to get within 50 calories at least.) You may be tempted to go under you goal for "better results," but don't do it.
How to adjust this to keep the scale moving in the right direction.
Once you begin to plateau or if you've gained weight 3 days in a row while honestly hitting your calorie goal then adjust your calorie goal by 8-10%. For example, if your calorie goal was 2,800 then multiply it by 0.9 (to take 10% off) and now you're new calorie goal is 2,520. Keep this goal for at least 7 days, before adjusting it again and it is better to wait to adjust it when the scales stop moving.
Exercise
Initially, I would set a goal for 10,000 steps per day. Which you can count with a pedometer, you can find them for under $10 these days. Now, if 10,000 steps are too intimidating, don't get down on yourself just set a lower goal that you will do every day. Then once you've, hit that goal for 7 days, then increase it by 500 steps until you get to 10,000 steps. I think you should also go beyond 10,000 at some point as well, eventually incorporate some light home workouts then join a gym.
Let me know if you have any questions.