Also don't hang out in the waves breaking on the shore for the same reasons. Sand abraision with a kayak on top of you is serious stuff. Wet or dry suits are highly recommended, not as much for comfort, but rather to assist in vital heat retension should you exit the boat some distance from shore. So keep that blade low while bracing, and getting out of the boat means exiting and leaving the surf quickly. Also, If you flip, tuck forward quickly.
Face plants are no fun in either rocks or sand.
This includes long paddle leashes that could entangle you when you capsize. Ask local surfers about nasty tides and currents. Be aware of high vs. low tide effects and what it is now. Paddling with a friend is recommended, both for the comraderie, and the support should you find yourself in trouble. When you join the crowd, consider yourself at the back of the line.