SALS LOCATION/TRAILS

Can someone possible help me? I tried to find Sals today and I think I did. I ended up near railroad tracks and a little parking lot. There also was a sign that did in deed say Walking Purchase Park. My question is, how do know what trail I'm on? I did see a little red square on a tree, but where are the other trails, like yellow and i think orange? Is there anyone that is going to be riding Sals in the near future that would be willing to show a beginner the ropes/trails?