I have an original reMarkable (not the 2) and whilst it’s a but slow for big fancy scanned PDFs it is generally pretty good for what I want. It does also run linux so you can ssh into it and do everything locally away from their cloud services which is nice
I found a personal tutor and I spend an hour with them every week (online). Outside of that I watch YouTube videos (with English subtitles) and practice with friends who I have who know the language too. I have tried Memrise, Duolingo and others in the past and I have made considerably more progress this way.
Basically: find someone who can actually make sure you’re getting something from it and find a good way to practice too