Ugh, where to begin?

My fiancee is from Poland. speaks immaculate English thank god, but most of his family does not.
I want to learn so badly, but can hardly make half the sounds (especially one that’s somewhere between a “ch” and a “t” in English…) He tries to help, but it’s hard for him to teach more than individual words.

Most likely going to Poland after the wedding next summer and oh boy, I need to get moving on this so I’m not 100% lost.