Everything in Cozumel is tourist friendly. Most merchants, hotels, and restaurants accept USD but will usually give your change in Pesos. Smaller Vendors, markets, and beach bars along the east side only accept cash (USD or Pesos.) You can bring Pesos home by requesting from your bank a couple weeks early or use the ATM Machines in town to withdraw Pesos at a lower fee. We prefer Ci Banco- make sure to avoid exchanging money at the aiport, it's much more expensive!
Shuttles, Private Car, Taxis, Rental Cars. See "Travel" Tab.
For restaurant recommendations, getting around info, recommended excursions, water sports, scuba diving/snorkeling, beach clubs, and all things Cozumel- check out the mother of the bride's blog guide here: https://www.wevegonecoastal.com/dorys-dive-logs and Cozumel Travel Guide here: https://www.wevegonecoastal.com/travelguides/cozumel-travel-guide. The bride's parents are locals and can give the best (and vouched for) recommendations around the island!