If you can't bowl, there are plenty of ways to improve your game without bowling, like read all of the tips and articles on
www.bowl4fun.com, learn Mo Pinel's dual angle system for laying out bowling balls to get any reaction you want at
http://www.morichbowling.com/You can practice your approach without a ball wearing socks and slide on a tile or wood floor. When you are walking down a hall way at school you can see if you can walk straight without looking by checking yourself against a line on the floor.
You can do squats to strengthen your legs, wrist curls to strengthen your wrist, and cardio to help your endurance.
You can also do meditation and visualize yourself bowling, strike after strike, this is the next best thing to actually bowling. If you break your approach down and visualize every movement to the foul line and visualize the ball going to your break point and making it's move through the pins, you will give yourself a good chance of actually doing this when you hit the lanes the next time.