Already tried that. It doesn't let me use both at the same time.

I recently set up retropie on my raspberry pi 3 b+ and I would like to use my joy cons as controllers however only one will work at a time when I load a game. After a few internet searches I found out that it is possible with Linux joystick mapper but I have no idea how to install it. Any ideas?

So I just got a raspberry pi and installed the raspian OS with NOOBS but I would like to try other operating systems to see which one I like best however I am not sure how to switch operating systems.

If anyone knows how to change between operating systems please let me know. Thanks in advance!