What not to do in Puerto Rico?

Answer 1

The same advice applies for any other part of the world, don't disobey the laws. Don't get stinking drunk in sleazy joints you don't know. Don't buy illegal drugs from shady characters, especially on the street, and be careful who you hook up with.

Don't walk around wearing lots of jewelry, nor have a big wad of cash when you pay, especially if you're out alone, especially at night.

Some beaches have strong underwater currents that may pull you under. Although it has a tropical climate, the best months -with the best weather- for beach and other outdoor activities are late April through early August.

Don't trust the mass transit buses to be on time.

Don't just stay in the San Juan metro area. Visit the smaller towns, where you'll get a better sense of the culture.

Don't just eat at McDonald's, Burger King, Subway, and the other stateside fast food places. Try the local cuisine.

Don't act like an "ugly American", because if you do, you are.