Magic eight ball is cloudy as to space, but there will be something, somewhere, probably not ideal for some reason, but magic does happen, be open to it. A smaller footprint is more versatile by Wednesday.
The box office is located just east of the post office where Pacific St. leads into Town Park. Loaded with camping gear and road-weary, you can try to talk your way into TP saying tix are at will call, but be prepared to be diverted to box office.
Bring stuff to keep warm and dry. Only other advice, do anything you can to get there sooner.
Read, read, read the threads above for Town Park virgins and TBF 101 for families, then ask more specific, customized questions.
Welcome