The Venice Beach and Boardwalk is an all time place for people watching. The types of tourists and locals who hang out here are pretty cool to see. I think just walking or scootering up and down is the move it you have some time to kill. Even in the rain you will see all kinds of folks out there playing basketball or lifting weights.
If you are in need of parking I encourage you to peruse the little roads that run up to the boardwalk itself, but you will likely have better odds on the more residential streets, as those don't attract quite as many tourists.