The UI is tricky but that could be said of any video editor other than maybe iMovie lol. Nonetheless, I've produced literally every video on my YouTube channel since about 2015-16 using Kdenlive, and would be happy to give pointers if there is anything basic that you don't know how to do (though I'm certainly no expert).

I have always been impressed by its automatic waveform-syncing ability, which even paid software I used prior couldn't do.

If you've ever used a video editor before, it's very intuitive and easy to use, and perfectly capable of professional results in most cases.

Save often, though :)

To find more good ones try out https://openalternative.co/, https://european-alternatives.eu/, and https://alternativeto.net/

Each of those list open source alternatives to all kinds of apps, games, etc