You don't have to eat anything before your workout if you don't want to, if you're lifting weights then you'll want to fuel your body with protein as quickly as possible after your workout to help your body build muscle.
If you're doing cardio then you don't have to worry about that, just make sure you don't eat a bunch right before your cardio session.
As far as what to eat, that's up to you, some people prefer the taste of fats (like Nuts, seeds, avacados, beans etc) and some people prefer the taste of carbs (Grains, Pasta, Rice, Potato, etc). You want to make sure your diet is sustainable forever, you're going to want this to be a life style change, not something you go on for 6 months, this is why alot of diets fail, because they aren't sustainable long term. You should be enjoying the food you eat, and you shouldn't feel like you're starving yourself, i highly recommend downloading an app like Myfitnesspal and logging your weight and meals everyday, it will give you a general idea of how many calories you need to maintain your weight, and your #1 priority should be going under that number.