my advice is cardio, mainly running. A good diet is key if your looking to lose weight, but a lot of cardio will get weight off fast, gain the endurance you will need for wrestleing, and get you in a good all around shape. Once you reach a weight you like start with a weight lifting program.
What ive found that works really well for gaining muscle mass quick is burnouts. (You will want to join a gym if at all possible) But for burnouts, start with a light weight that you can do 12 times. right after that go up ten pounds, and do it 10 times. then up ten pounds and do it 8 times, then up ten pounds and do it 6 times. Then take it back to the weight you had it on for 8 times and do that twelve times. The muscels that youve just worked will be tight.
I would break it up like this: Monday - upper body. Tuesday - cardio/abs. Wednesday - legs. Thursday - cardio/abs. Friday - upper body. This is a good start out program.