Welcome to the forum and above all, congratulations for your engagement!
In order to get a marriage license in Mexico, there are indeed requirements:
Valid passport (valid for the bride, groom and the 4 witnesses)
Tourist Cards (which you will receive while entering the country)
(valid for the bride, groom and the 4 witnesses)
Apostille certified birth certificates for Bride & Groom
If applicable, final Record of Divorce
If applicable, Death Certificate
Health certificate and blood test provided by a Mexican Official
Moreover, a blood test must be taken. The test must be taken in Mexico and should not be taken more than 14 days prior to the ceremony. The blood is tested for HIV, RPR (sexually transmitted diseases) and blood type. Results are ready within 24 hours together with a certificate of the blood test.
Do not worry though because the wedding manager is here to follow you and can deal directly with the local officials to coordinate the legalized wedding process.
Have you thought of the Riviera Maya? One of the best things about Riviera Maya is the fact that you can get everything you dream, and it goes from the simplest things, up to the most elaborated... I am certain that you would love it.
To check out various resorts, a good place to go is the hotel review section on tripadvisor.com and the venue reviews here. TA will not offer many wedding reviews, but the list is probably more extensive and you can come back here to learn more about wedding experiences. I would suggest using both resources.
Your wedding is going to be full of magic and this website will help you a lot!
We wish you the best.