You book this place on HipCamp, $20/person/night (though you could probably pretend you're one person)...showers, bathrooms, communal kitchen, wifi, and grass. I parked in the North side of the parking lot away from the office along with the other car campers.
The bookstore has a very VanLife and campy selection. It's close to a highway and can be intermittedly loud, so bring earplugs.