It is possible to find very cheap flights to Cancun International Airport (CUN), in the middle of famousMayan Riviera resorts, from abroad. There are many connections to Mexico City (Volaris and Aeromexico flights are suggested).
To arrive from there to the Historic Center the safest and quickest option is to book a cab, you should do this from one of the authorized modules inside the airport, some are located just at the luggage bands, and some are passing the arrivals doors. Here you can find all about authorized cabs Prices may vary from module to module and the final destination.
You can also arrive by metro or metrobus (you may need to change the bus once), it will take a longer trip though and be sure you study the route in advance...
Uber is not recommended to go from the airport to the hotel, since sometimes you have to walk out of the airport, but is ok for moving around the city and to go back to the airport.
We just recommend you to take the standard precautions whenever you are in a very touristic and crowded area. Be very careful with your belongings.
We highly recommend that you do not take a taxi in the street. Use safe taxis provided by your hotel or Uber, Didi, etc.
Do not eat in the street. There are plenty of restaurants close to the venue and the hotels.
Do not drink tap water.
https://travellemming.com/is-mexico-city-safe/
Medical attention is tipically from private consultation, so we recommend you have a travel insurance.
The visa requirements to enter Mexico can be found at:
https://consulmex.sre.gob.mx/washington/index.php/servicios-para-extranjeros-visas
Letters of invitation for VISA purposes will be available upon request for registered participants.