The funny thing is that the native language in Valencia isnt Spanish-Castillian, but Valencian, which is a dialect of Catalan (though its probable that a Valencian would say Catalan is a dialect of Valencian. Its Spain. Thats how it goes).
The Valencians dont make as much of an issue out of it as the Catalans do, though. Over there Catalan is required in scools, signs and official everything is bilingual Spanish-Catalan. Rather like in Canada. Not so much in Valencia.
Catalan/Valencian are quite different from Spanish btw. Until you get very used to it they are not really mutually intelligible.
The biggest common differences between Spanish in Spain and Latin America generally is that the “colonial” language was filtered through Andalucia, as Sevilla was the principal port of access and point of governance to all the Americas. And Andalucian (yet another Spanish accent/dialect/language) itself can be quite peculiar.
Latin America has a common “television” dialect, which is what you hear from Telemundo, etc. Also most international media and entertainment.
I rather like the Mexican accent. The “educated” version is “easy listening” and pleasant.
Interview with Natalia Lafourcade (from Veracruz)
https://m.youtube.com/watch?v=xciXjV_a06I
People who refer to Mexican Spanish as “low class” generally don’t know what they are saying. Educated Mexicans speak quite clearly and well, as for that matter do educated people across Latin America. What happens is that if you aren’t a native speaker small differences in regional speech and even more with uneducated speech are a problem, but a problem that passes with exposure.
The same problem happens in reverse with foreigners in the US when they are exposed to, say, “countrified” American English. Or regional British accents.