1
Pack the right clothes. Pack the swimsuit you've picked out and an extra change of clothes. The extra change of clothes is for the ride home, so you won't be all wet and sandy.[1]
Also, make sure your comfortable enough to spend all day in the clothes you wear down.
Having a changes of clothes means you can head somewhere else after the beach.
Don't forget to include good footwear. Take sandals for the beach and water shoes for the ocean so you're ready for anything.