Cuban Spanish is its own beast, I think it’s like speaking California-American English to a person with a thick Scottish accent, you kinda have to slow down a bit until you get used to it. Source: am a Mexican native Spanish speaker who’s traveled to Cuba.
Ah, word. It's what most US-ians in movies sound like because of hollywood and therefore it's mostly what folks consider "American English". It's not the default though, because there's also western/texas/deep south english which is your typical cowboy to hillbilly range of accents seen in wild west movies, or when coastal libs do that annoying thing here equating all southerners to inbred reactionaries. The Midwestern accent is a bit on the stereotypical Canadian side, at least to me, and the New York/Boston/New England accent is also sharply distinct. AAVE (African American Vernacular) can also differ among regions and is different from how non-Black US-ians talk in many cases.
I feel kinda guilty sometimes when I spell Amerikkka wrong, forgive me I'm still kinda new here lol! Good luck learning Spanish, it's certainly closer to Danish or English than Mandarin is :)