I just practiced for track yesterday and my upper legs are sore. what do i do?

Rest: Conditioning is important in sport : proper warm ups, streching. Make sure if you do lift weight, that you have proper rest, and don't over do it. May need intervals of 24-48 hours rest, you can do other kink of trainning while resting. It is quite dynamic and fun but requires the proper person to coach a good routine for you.

It's normal: Soreness will go away, as long as you keep on exercising.