It’s Heavily Influenced by the United States

Many people believe Puerto Rico is an independent country, although it is actually a United States commonwealth. This also implies that it is greatly impacted by all things American, such as fast-food restaurants, retail stores, car repair shops, and so on.

This also implies three things that will make your journey easier: One, you don't need a passport if your government-issued identification will suffice (you do undergo an agricultural inspection on your return trip, but no customs or immigration in either direction). Two, Puerto Rico uses the same electrical outlets as the United States, therefore converters and adaptors are unnecessary.

Three, because Puerto Rico's currency is the US dollar, there's no need to worry about currency exchange, albeit the ATM may charge you a foreign transaction fee (though likely not by a credit card).