What's the best way to (start) learning a language?

I traveled to Japan for a few weeks last year and had grand plans to learn a bunch of phrases, but got lazy and punked out. I still had a great time, everyone was super kind, but it was embarrassing how well so many folks spoke English and I couldn’t even be assed to put in a bit of work.

My wife is half Mexican and we’re in California, and she gets a lot of people initially talking to her in Spanish, which she can’t speak beyond an ordering food level, and would like to change that.

What’s the best way for us both to get to a beginning conversational level in Spanish? I tried Duolingo a while ago and it was eh, and I’ve heard it’s all AI these days. Any other recommendations?