there's more Spanish speakers in the US than in Spain

A lot of that is just... the US is huge and Spain is not -- the population of Spain is 44 million and the population of the US is 314 million. And despite the large number of Spanish speakers in the US, English remains incredibly dominant. The majority of Americans only speak one language because they have no reason to learn another one. Hell, I've studied four languages and I have a terrible time finding ways to use the non-English ones, to the point that I lost one entirely and can only passively understand another.

I grew up in Los Angeles and my Spanish is restricted to stuff found in songs for preschoolers (I can count to 10, recite the months of the year if and only if I do them in order, and say 'hello' and 'goodbye'). In a sad display of stereotypes, the only time this has caused me difficulty was when the guy my parents hired to mow our lawn when I was a kid tried to tell me something (which I eventually figured out, from context, was along the lines of 'Miss, there is a giant beehive in your yard and I can't mow the lawn because I am being attacked by bees.').

tl;dr: I cannot overstate how little this matters.