Can you just smoke weed, enjoy the music and not talk to anybody? Is that sort of experience possible?
You can, but a big part of the marvel is in walking around (er, biking) and seeing the spectacle. If it's your first year, that's your job: be the audience.
Smoking weed is iffy; lots of federal cops out here looking for it, since pot is still illegal on federal lands.
Just chilling and doing your own thing is certainly doable.