The tent is the smallest part of your trip there. Do like the others have said and just shake it out or sweep it out as needed. Unless you're gonna put a tarp down the size of the beach you won't keep the sand out. Hell, I think I still have sand in my trucks from the first time I was there back in '90. Been going ever since.
Either way have fun!
What weekend you going? we're going in Oct. too!