Student or Learner
Do you say: "Enjoying the vacation at Miami Beach" or "Enjoying the vacation in Miami Beach"?
If you are actually talking about the beach itself (ie the sandy part next to the sea) then I would use "on" - I'm having a great time on Miami Beach.
If you are talking about the city of Miami Beach, then I would use "in" - I'm really enjoying my vacation in Miami Beach.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.