There are Telegram groups where people can help you. A while ago I was researching on a similar device, there are really so fricking many and they all are slightly different.
You definitely need a quality SD card to replace the cheap knock off card that came with it.
If you are very lucky, there is a way to boot something like emuelec, Lakka or similar alternative OS, maybe you will be lucky and find a backup of your exact stick. It is good to have photos where you can read the name of the chips and fro mthe packaging with all numbers. Some of them are on archive.org There is also some kind of russian language forum, where they offer all kinds of alternative OS solutions but for the one I searched, there was only a backup of the original menu, which worked fine after getting the brand SD.
Maybe check the resellers website or offering or contact them, if you can not find something.
Good luck.