Chichen Itza was good for history/archaeological information. Long bus ride to get there, take a chartered tour, since a good guide can make or break your experience. The ball field (seven echoes) was a trip. We stayed for the evening light show and were incredibly underwhelmed. It was not worth staying late for, although we did swim in a Cenote (Ik kil?) and that was incredible.
Other couples swam in other cenotes and loved every one.
Tulum / Xel-Ha was nice. IIRC, Xel-Ha is an ecological water park and was a good trip. Tulum is kind of a very early settlement, but the cliffs overlooking the beach were very nice.
You'll probably come across free trip offers, just to come out to 'visit' a time-share place. We did that for some Grupo Maya timeshare, and were surprised to find that they were very pleasant, not dicks at all like I've seen in these parts. No, we didn't buy.
You might be tempted to visit Jimmy Buffett's Margaritaville. Maybe you'll like it. They made a good margarita, but that was about it for me. Good luck on your trip.