Fruity Cocktails

Pop / fruit cocktails commonly ordered for beginners ..?
I turned 21, while doing one, and I never know what to ask in the bars! When I go on the websites of recipes, I think the drinks that sound good, but I am always afraid I will ask one of them and the waiter did not have a clue what it is! Any waiters or anyone with a knowledge of what is common and popular drink have any suggest? I like rum, pineapple juice, orange juice, grenidine all good stuff … any suggestions?
sex on the beach, grape crush, Pearl Harbor, Grateful Dead, pineapple upside down cake … just watch with the sugar in these drinks packs on the pounds and makes for a nasty if he had too much fun
Fruit Cocktail