My partner is from Morocco. The country speaks a specific dialect called Darija, a fusion of multiple languages, that isn't spoken much outside the region (it's not even recognized on sites like Google Translate). Tips on learning a dialect that is more "niche" and not as widely acknowledged?

I am a monolingual English speaker. I am hesitant on where to start when it comes to learning my partner's language, as there isn't as much academic resources for me to rely on as with other languages. I was just wondering, for those who are learning less commonly spoken languages/dialects, what methods helped you the most? Because this language is a fusion of several languages, should I learn the basics in the languages it combines before learning it, or jump straight into the dialect itself? I want to be able to have a conversation with my partner's family, who don't all speak English. My partner speaks fluent Darija, Arabic, French, and English, so I'll have someone to practice with if I choose to learn another related language first. I am just nervous about the process of learning a language that is not the most accessible.

Thank you so so much!