Recs for traveling between Mexico cities?

Hey all,

Booked honeymoon trip for next month in Mexico. Doing cancun for a few nights, tulum, and then México city before flying back to the states. Any tips on how to travel from cancun to tulum? Safest/cheapest options?

How would you recommend going to cdmx? Drive back to cancun from tulum then fly there? Or are there direct flights to cdmx from tulum?

Thanks