Playa Del Carmen was my favorite area we visited on our trip to Mexico. With only one day dedicated to the area, we opted to stay close to 5th Ave. 5th Avenue is a street lined with shops, restaurants, hotels, cafes, etc. that runs for 3 miles and is just blocks aways from the water. There’s definitely locals trying to sell you stuff, but if you can block it out, you’ll enjoy yourselves. There’s a ton of cute restaurants you can stop into, we happened to stumble upon Ambasciata D’Italia and it was fantastic! You’re always hesitant to try non-local cuisine especially in a place like Mexico (hello Mexican food!), but this place was GREAT! They even had gluten-free pasta.
If you’re visiting the Baja/Caribbean side of Mexico, I would highly suggest staying in Playa Del Carmen and even on or just off 5th Avenue. Not only will you be close to everyday necessities (food, night life, etc.), but Playa Del Carmen is actually a quick drive or taxi away from Cancun, Riviera Maya, and Tulum.