Thats a pretty big question!
Concerning food. With powerlifting, just make sure you eat plenty, you don't need to eat like a bodybuilder or anything as strict as that, just make sure you get a lot of good food, with all the necessary complex carbs and loads of protein.
Theres not gonna be one routine that you can do, so it might be a good idea for you to do some reading on the internet. Look at
Those sites will advocate a westside style routine (splitting your workouts into dynamic and max effort days, doing one big exercise a day and then a couple of assistance exercises.)
Probably the most important thing is not to waste your time doing things like bicep curls. Powerlifting routines are also very simple and straightforward, with low reps and high weight.