We loved the white sand beaches in Cancun. It’s actually not sand but crushed up shells, cool on the feet.
Been to Cancun, too. It was pretty, but I prefer Puerto Vallarta; vacationed there twice.
Went to Acapulco when I was 17 after I graduated High School. 1977, then I joined the Army. (US, NOT Mexico, LOL!)
Went with my BFF at the time and we had an absolute blast for two weeks. Don’t tell my Mom, LOL!