Pushups, situps, pullups, you can switch these up to work out lots of you.
Do plyometrics for your legs, too.
examples: pushups, diamond pushups, pushups with one hand, clap pushups, knuckle pushups.
Situps, situps with your legs up, crunches, leg raises, situps with left/right elbow movement to touch the knee, same with your legs up, holding your legs out straight about 3 inches above the ground.
pullups, chinups, wide grip/close ground/shoulder width of the 2 basic exercises, knee raises while you're hanging lift them to the chest, monkey bar movement about.
Lunges, squats, jumps, jump and reach for the sky, jump and lift your legs up to your chest.
Also, get a skipping rope. Helps loads.
You can get pretty fit from the above.
You'd have to do a lot, and add weight to your exercises after a while, after you've built up to a certain amount of reps.
I won't tell you reps, just do more than you did the previous day, change the exercises about with the examples i gave.