A big thing in gymnastics would be the flexibility. The major ones would be your splits, your bridges, your shoulder flexibility. The split though, however, is very important in order to obtain the gymnastics that one desires. The split should be what we call square.
The hips should be turned forward, not sticking out sideways. So both hips if like they were headlights on a car should be facing straight ahead. Also, the back leg, you should not be able to see your back knee. As if you were wearing shoes, you want your shoelaces on the ground, your legs straight behind you. So your whole bottom back leg is on the ground underneath of you.
Front foot should not be turned in or out, it should be straight ahead. You should not be able to see your heal. The bottom of your front knee should be locked on the floor. So the bottom of your knee should be able to touch the floor.
Your back should be nice and kind of a little arched back. Chin up. And you want to do it to where you don't even have to use your hands, where your arms can go out to the side. That would be a correct gymnastic split, which leads into leaps on beam, on floor, and initially, getting you to the higher gymnastics.