Taking the ferry to Cozumel from Playa Del Carmen is pretty straightforward. Once you get to the port at Playa Del Carmen, you can choose which company you want to ferry with. While I was there, only one company was running per day. I am not sure if that happens all the time or if it is a new process with Covid. If that is the case, then you just need to buy the ticket for whichever company is running that day. The ferries run from 6:30 am-11 pm and the journey is 1 hour. It is easy to make a day trip to Cozumel from Playa Del Carmen and many people do. Once you get to Cozumel, you are dropped off right downtown or there are plenty of taxis to take you to your first adventure on the island.