My rule of thumb-
Don't be the first one on the track in the evening if possible
Enter and exit from the pits.
If you see a security person ask permission first.
If some one stops you say you are sorry immediately and get off the track ASAP.
Always pick up any debris when walking the track.
If you are riding you bike wear a helmet.
Never try to take a scooter or any other powered vehicle on the track.