In Mexico, marriage laws vary from state to state, same as in the United States.
If you intend to marry in Mexico, you will need to contact the Registro Civil (civil registry) office where you plan to marry. They can supply you with the complete details about the requirements that you will need to satisfy to obtain a marriage license.
Some jurisdictions in Mexico require that the bride and groom both take a blood test and have a chest x-ray after arrival. The results must be presented in Spanish, and foreign documents must be translated into that language. Learn more at Mexico Law.
Note: If you are marrying at a hotel with a wedding coordinator, she may be able to help you fill out much of the required paperwork.