OBS is the gold standard for recording but it may be a bit heavyweight for your liking.

Soundux is a good but maybe a bit confusing soundboard

SimpleScreenRecorder never failed me. Does what it says.

You could also try Kazam.

https://github.com/henrywoo/kazam

screen recording and/or streaming (preferably lighter weight)

VLC can do this. The streaming part might be tricky because it won’t do the networking for you, but it’s easy enough to screen record to a file.