I'm scared of something silly?

I'm really exited because next week we are going to the beach!! It's just, I always get scared in the ocean though, my friends always come back saying they got stung by a jellyfish or pinched by a crab, and one of my friends even told me they got stung by a sting ray!!!! I'm sooo scared to go in the ocean, i just don't want the animals to hurt me!!! I have been to the beach and to the ocean before, and i usually don't go farther than a foot into the water because i'm soo scared of whats in it. It's also somewhat dirty water, so I cannot see what is in it when i'm swimming. HELP???