For this sentence, tip is the correct choice. You would use "tip" when talking about advice, for example, "Here's a tip - get to the movie theater early to avoid long lines," or "The bus driver gave me a tip and told me not to go to the museum on Saturdays because it's too crowded."
The word "hint" is used more in the context of clues. For example, "I can't figure out this crossword puzzle. I need a hint." Or "What did you get me for my birthday? Can you give me a hint?" (An answer might be, "No, I'm not telling you anything. You'll have to wait until your birthday to see what I bought you." )