Clothing is a very important subject in gymnastics.  If you do not have the proper clothing a spotter (coach) or yourself could get hurt.  The proper clothing that you should wear is a leotard or a tight shirt.  You could wear your leotard with a pair of shorts or pants, but like the top they should be tight fitting.  You should never wear baggy pants or a baggy shirt, if you did the spotter would be in danger of tangling her/his arm in your shirt and he/she could break their arm.  In this process they could drop you and you could be badly hurt.  For gymnastics you do not have to wear any shoes.

For gymnastics you should always wear your hair back in a bun or a pony tail.  If your hair is too short to wear it these ways pull it back in a half pony tail or use a head band.  If you do not have your hair back it could go in front of your face enabling you to see and you could fall and get hurt. 

This is a picture of what you should NOT wear and wear your hair.