We went to Puerto Rico when Baby Monster was almost 3 months old. It actually was pretty easy to travel with him at that age, and it was super helpful having my mother and brother there to help out. That was a picture of him sitting on our king size bed in our hotel room.
For the most part, it was easy to do many things with a baby in a stroller. It was also helpful that at the time he could sleep anywhere. Old San Juan was an excellent adventure with many things to see, especially for someone very new to the world. And Old San Juan is pretty stroller friendly. We also did the Bacardi Tour, which was also pretty stroller friendly. You have to break down the stroller when you are on the tram ride to the distillery, but then you can set it back up when you get there.
Helpful hints about Puerto Rico. It’s like traveling to another city in the US, except they also speak Spanish (they all know how to speak English). So you can definitely find creature comforts you would expect back home. This includes formula and diapers! So we packed just enough diapers and formula to get us through traveling for a day. Once we arrived to our destination, we went to the local grocery store and stocked up on what we needed for the baby. And leave the travel crib behind if you are staying in any hotel. Most have pack n’ plays for your baby. Just call and make sure they have them, and when you check in, remind them again that you need that set up ASAP. Finally, pack a lot of light cotton clothing! It gets hot, and you want breathable fabrics for your baby.
Also, before you go to Puerto Rico, ask your pediatrician about water. We went in November, and it was soooooooo incredibly hot. Some may recommend giving more formula or breastfeed more, but others might say a little water is ok. The same thing goes for sun tan lotion when they are super young.