My only experience in this area (Single Board Computers) is from about a year and half ago: I set up a Pi3B as media player (essentially for the children). I installed LibreELEC (a very lean Linux just for this purpose) with Kodi (the media player) on a SD card which just worked perfectly, put it into a cute little box, added a soft button for boot and halt, connected a small wireless keyboard with trackpad, added remote read only access to the family NAS and installed a few kids compatible apps. Since then, it works fine and the TV has a purpose again, as it is practically unused otherwise as Samsung’s SmartTV apps cannot be updated on this model, so it is a huge “dumb TV”, a monitor connected to devices.
The only thing complicated was making the YouTube Kids add-on work which required manually copying a lot of very long authentication strings. In the end, it worked.