probably goes without saying but typically early morning/late afternoon will give you the best (most interesting) light. glidecam and 11-16 prob won't be of much use except maybe for some pre/post surf lifestyle shots like waxing the board, putting in the fins, etc.
definitely use a tripod and the tele lens for footage from the beach; it will probably take some practice to track him smoothly but play around with different zoom lengths and framing. also look around for interesting features to include like wildlife, lifeguard stands, other people, driftwood... don't be afraid to go down the beach a bit too so you're at more of a diagonal to him rather than facing him straight on.
with the gopro you have a bunch of options so just do whatever comes to mind. u can swim with him in the lineup and get as close as possible, or have him hold it or mount it on the board. could also just get some empty wave shots with it in the barrel (assuming it's barreling).
kind of obvious but remember it's really sandy and usually windy so be sure to protect your gear. try and clean off the tripod as best as possible before collapsing the legs so there's not a bunch of sand grinding around in the little spaces.
that's all i can think of right now but as others have recommended just watch a few edits and get some inspiration.