Workout and Diet Advice

I am injured and will be receiving a surgery to repair a labral tear in my hip. I'm only 20 years old and fairly athletic, but I'm no gym buff. I feel like I keep gaining weight, but I don't know any good workouts or diet plans to lose any of it. I've been struggling since I initially injured myself to find anything effective. Does anyone have any advice for me until I can get back on my feet?