Actually, what I found was that in Duolingo I was learning random, specific versions of verbs such as Quiero (I want), Quiere (she/he wants), Quieres (you want). But I should have been learning the verb starting with the "to form", e.g. Querer (To want). From that you then learn how to conjugate the different variations based on the use-case, which isn't just I, she/he, you, they, we but also is different in the various tenses. But having blindly learned words in Duolingo without explanation is hampering me, I kept reaching for say Quiero and not Querer as I should and then the rules for breaking down the verb and adding the right ending don't work right.
I wished I'd started with LT, learned the rules, then maybe Duolingo would have been ok for practice (although the gamification sort of annoys me). My Super Duolingo sub is up this summer, I think I might not renew and stick with LT and Dreaming Spanish.
Regarding Latin American Spanish vs European -- in the LT lessons, they cover the differences in pronunciation when applicable and also differences in word usage (Carro vs El Auto) and even later on talks about "Spanish Idiolects" (e.g. the ways individuals speak Spanish).