Getting around Puerto Rico is the key to having fun! Get out of your hotel, there is much to see and much to do. You do have a few options, which I'll detail below:
1. Public Transportation
Generally does not exist. There are limited-area shuttles and trains, but generally not something you can count on.
2. Driving - You
First a note on driving in PR: People will tell you to be scared to drive here. If you are a fairly confident, defensive driver, you will have no problem. It's not so much speed, but traffic laws are minimally enforced, thus heavily taken advantage of. It may be a little outside your comfort zone, but you're in Puerto Rico, and driving is nothing personal to locals. Also note that one cab ride generally equals one day's car rental... Absolutely make sure that your credit card or home/car insurance covers rental cars or take the rental car insurance option. [All the major rental car agencies are at the airport, Hertz, Avis, etc.]
WEDDING TIP: Kenneth Car Rental [787.888.7000] is on the primary Road #3 in Rio Grande, and can provide standard cars, as well as large passenger vans that can be rented for a day to get your group from one place to another. Great for wedding groups the night of.
3. Driving - Cabs/Uber
Uber is very new in Puerto Rico and not yet effective. It is growing in metro San Juan, but Uber can't service the airport and isn't established in most suburban areas. Cabs are a viable option, and cab drivers are generally friendly and knowledgeable, and either speak English or they'll get someone on the phone who does.
WEDDING TIP: If you just need to move a smaller group once - and don't have too far to go - you can arrange for several taxis to transport your group at a specific time, and even arrange for departure at a specific time. It's less organized, but a good option if this meets your specific needs. I recommend Luquillo Taxi [787.513.7685]; if in San Juan, Puerto Rico Taxi [787.945.5555].
4. Driving - Professionals
Limos, town cars, transit vans and buses are all available and professionally operated. These are great for traveling in style for special events (3-4 hour rentals are standard) and moving lots of people. Drivers are very knowledgeable about the area, and can make stops at scenic stops or happening bars so everyone can stay "hydrated".
WEDDING TIP: Royal Star Limousine [787.253.2355] operates island-wide, and can accommodate 2-300 guests in gorgeous, luxurious vehicles. They can customize your experience, for example moving all of your guests at once in a large bus to a location such as the Luquillo Kioskos for dinner, and then running a shuttle back to the hotel throughout the night so guests can return at their convenience. Make your wedding night perfect and let professionals drive you around all night!