Asklemmy

I'd start by joining a language learning community. I never saw one when I was on Reddit, but the biggest one on Lemmy is over on Hexbear: !languagelearning@hexbear.net — there are others if you don't fancy Hexbear, but Hexbear's has twice as many subscribers as the next largest one. Or join multiple.

I'm not really one to give advice. I know a few words in a few different languages (including Japanese and Spanish) but I've never gone so far as to learn another language. So I'm really not the best one to ask.

As far as method goes, I never had luck with Duolingo, either. I've heard the best ways involve private tutors, and joining language exchange communities. These, I don't know about any specific ones. But the idea is, you (and your wife) want to learn Spanish, so you join and people who want to learn English but know Spanish work with you. They help you with Spanish, mostly by talking to you (or typing to you) in Spanish, and what you don't know, they help you with. Then you talk to them in English and help them where they need help. And you learn together, as a team.

I love Japanese and I listen to Japanese music. I also go to Japanese restaurants and attempt to speak Japanese. I do let them know I'm learning and apologise in advance if I get something wrong. For example, Japanese uses double vowels which can be tricky. The word yuki means snow, but the word yuuki means courage. (These can also be used as names. And no, I don't know the Japanese glyphs.) They both sound like they look, but you would pronounce the U ("oo" sound) twice. "Yoo-key" or Yoo-oo-key." But Japanese people would do it quickly, so the latter sounds more like "Yooo-key" (note the extra O). Though I think if you're pointing at snow and hold the U sound too long, they'll know you mean "yuki" and not "yuuki."