I used to do parkour and freerunning almost every day for a period of about 8 years. I used to teach a parkour class at a gym as well. Let me tell you, the extreme stuff really -blam!-s you up. I have some pretty serious spine problems now and a bad shoulder. Always remember to practice safety and don't do a lot of extreme / physically intensive stunts because it will catch up to you later twofold. I wore whatever was comfortable. Usually just a good pair of running shoes, shorts, and a T-shirt. Parkour apparel wasn't a thing when I started training.