For a first time I recommend a jeep on St. John so you can see the whole island, its not big and won't take long but I like the option. Also, unless you are at the Westin or staying in Cruz Bay you'll need to car to get from your villa to the beaches. You can Taxi to Red Hook ferry and get your ride in Cruz Bay or you can get a car in STT and take the car ferry. There are pros and cons to both. Jeeps in STT are cheaper but if you have problems on island renting in St. John is better. Also, many rental places let you park at their site in Cruz Bay as parking is pretty limited. If you go the taxi route while on St. John you are more limited to the beaches you can hit, all of which are amazing but you miss out on Francis and hiking to waterlemon for snorkeling. I've also fallen in love with Salt Pond, which is on the other side of the island, where I think the best snorkeling is. If driving isn't your thing, staying at the Westin or in Cruz Bay and taxing to Hawksnest, honeymoon, trunk, cinnamon and Maho work fine. All of those are about as good a beach as you'll find anywhere. Maho is known for turtles and rays. Trunk is the most famous. Honeymoon is stunning. My wife's favorite is Hawksnest, its chill. I like to explore so I alway get a Jeep. We stayed in Cruz Bay once when we were there for just a couple of days looking at a sail charter business and enjoyed it much more than I thought I would because you could walk to all the bars and restaurants and we took a taxi the day we weren't sailing to Trunk.