As a traceur, I believe I'm qualified to tell you that this is a poor idea. The discipline of parkour or free-running is mentally and physically challenging. Without significant prior training, you seriously risk injuring yourself performing even simple vaults or passement techniques at speed, on unfamiliar and uneven terrain, and while wearing a bulky costume. Furthermore, expect severe repercussions from administration; they're supposed to be responsible for your health and safety during school hours and won't take kindly to you endangering yourself in an off-limits area of their property for a silly stunt.
