Mexico City is a large modern city. Credit cards are widely accepted at the hotel, sit-down restaurants, and shops. Restaurants generally do not split the charge so have cash if you plan to share the bill with someone or if dining at smaller, more casual venues.
Museums generally do not accept credit cards. They are all relatively inexpensive but plan to have enough cash on hand.
You should plan to exchange a day or two's worth of money at your local bank before leaving your home country to get you to the hotel and settled into the neighborhood. Check with your local institution to understand their conversion rate and procedures. Small bills are highly recommended as many places cannot provide change for larger bills.
Banks, ATMS, and casa de cambios are plentiful options while looking to exchange or withdraw money while in Mexico. There is a Santander Bank ATM in the conference hotel lobby for convenience. Look carefully over conversion rates and fees before accepting transactions. Below are various resources to help you figure out a plan for exchanging money. Your bank may be part of a network with Mexican banks and offer no-fee ATM access.
Forbes (general guidelines for exchanging foreign currency)
For tipping guidelines see Frommers and Tripadvisor (scroll towards the bottom of the guide)
As of February 2022, the conversion rate is roughly:
1 USD = 18.50 MXN
1 CAD = 14 MXN
1 GBP = 22 MXN
1 EUR = 20 MXN
This rate may alter slightly over time and depending on where you are exchanging money. You can check this rate through your local bank and other financial institutions such as Bloomberg or the Wall Street Journal.
This app is a convenient way to convert US dollars to Mexican pesos. It is a good idea to check a variety of sources to get an average of what to expect when you are looking for a place to exchange money while in Mexico.