31 days until wheels up to Cancun with 2 of my old high school friends. All 3 have never been to Cancun. Staying at Grand Oasis Cancun.

Suggestions on excursions for 3 females in their mid-30's? We are looking for some fun things to do a couple days out of 7 day vacation.

Also...money. Should we rely on credit cards or would it be better to bring cash and exchange when we get there? For staying in all-inclusive, how much would one suggest to bring with us? We do want to go to some of the bars in the area, a little shopping & of course excursions.

Thanks in advance for all your help.