probably one of the best free video editing programs out there atm is davinci ( https://www.blackmagicdesign.com/products/davinciresolve/ )

for simple editing though I used to use KDEnlive a lot, pretty easy to wrap your head around, allbeit with a few quirks that take some getting used to ( https://kdenlive.org/en/ )

I’m sure theres others but those are the two I’ve used personally.