careful how you phrase things, there. Some of us take great pride in being high school gymnastics coaches. You made a choice to join, be proud of it. That's the first exercise you need to do.
From there, most high school gymnasts lack flexibility and range of motion. If you have your splits, work on range of motion. Make sure you can flex your muscles while in the splits and hold that flex for 10-15 seconds. While youre at it, work on over splits. Work on pancake positions, bridge work, and shoulder flexbility.
For arms, since youre a bar lover apparently, handstands are your friend. Hold them straight against a wall for 1-2 minutes for stamina. Then work on rocking side to side (picking up one hand and touching your nose is usually a fun way to challenge yourself). You can start doing these against a wall until you can do about 10 (so, 5 each arm), then start doing them free standing.
Hollow planks (where you rest on your elbows in a "prone" (like a push up on your elbows) position), will help make sure you have a good hollow position. Having a parent or friend put gentle pressure on your hips in that position will help you feel some of the negative pressure you will feel from swinging and flipping.
Other than that, just play - really. Back walk overs, front walk overs, handstands, pirouettes, jumping, landing... whatever you do for fun. Even rock climbing or bike riding can help increse your over-all health and well being during your off time. The stronger you are, the less prone to injury you are. The more you learn to use your muscles, the less likely you will flip out and get lost in the middle of training.
Love the sport youre in. Be proud that in just a few short years you can potentially keep up with people who have done it for 10. I have coached many girls and boys to learn many of the skills that we see from "club" gymnasts in those short 4 years, and all of them felt successful for their own ability level. Compete against yourself and you will always win.
Good luck to you, and stay strong.