Place Rec for 18(m) solo traveling

Hello everyone! This summer for my senior trip im planning to do a solo travel(or with a buddy) to either Costa Rica/Puerto Rico/DR

I’m basically looking to travel to a place that’s affordable ,surf almost everyday , eat good food, experience new things , explore cool places , and meet new ppl!

If anybody has any advice or recommendations on which of these places I should plan to go to any info will be appreciated. If im going to CR I was told to stay in Tamarindo but idk.

I’m planning to buy tickets within the next two weeks and leave mid June.