You might have issues with permissions for serial ports on some distros, but there are loads of easy to follow guides for that. Linux definitely handles them better than windows though. I never had issues where they just stop working like on Windows.

KiCad. It’s an electronics design tool on par with commercial options in the industry, which cost a ton of money. Ever since the UI facelift it got a few years ago, it has become my go-to option. They are even working on integrating circuit simulation and finite element analysis, which is just crazy.