Where do locals hang out in Cancun?

[ChangoDeMadera]

I want to venture out to the real downtown in Cancun this summer when we go.
How is Market 23 like? Where are some clothing stores locals shop at?
What public beaches can we go to? (We went to playa delfines once).
What good shops/ restaurants can we go to?
Are there any cenotes we can explore ourselves nearby?
Tell me what cool places you know of that tourists do not visit much that we can explore on our own and what suggestions you have about how to get there and when to go etc?

My bf is Mexican and I too speak Spanish so the language will not be a problem if we venture out to places where English is not spoken much.

Thanks!!

Timea