Have a look at DietPi. That is a single-board-computer optimized Linux distribution that, in contradiction to what the name might suggest, runs on (almost) all of the SBC’s out there. It has stripped away all the things you don’t need and only installs and loads what is needed to run the software you choose, resulting in a very lightweight but powerful operating system for these kinds of devices. It has its own software catalog with a broad selection of optimized software, but you can of course install anything you want. Ive been running this on a Raxda Rock4 without any problems, and would definitely suggest this even on a Raspberry over the regular Pi image.

I stumbled upon Mondly recently, which is great for learning a language and does a much better job at actually teaching and explaining than Duo does. It’s also cheaper, less gamified (but still fun) and eu-made!