What should I set up on a new Windows PC for light video editing?

Start with Windows Update, including any offered driver updates, then check the computer manufacturer's support page for anything still missing. For the Radeon graphics, check AMD's driver options too. Once everything is installed, restart and make sure the display, audio, network, and storage are working.

Set up regular backups before you start collecting projects. Keep copies of both the project files and the source footage, since the project file alone may not contain the video clips.

I'd try Kdenlive first for lighter editing, then give DaVinci Resolve a go if you want to compare. Test each with a short clip from your actual camera or phone before committing to a big project. Playback, export speed, and support for your footage format are more useful tests than a feature list.

If playback is choppy, look for proxy editing settings. Proxies use smaller working copies of your footage while you edit, while the original files remain available for export.

There's no need to install Linux just to get started. Windows is already there, so try your editing software and games on it first. That gives you a baseline before you decide whether another operating system is worth the setup work.

If Linux sounds fun, pick either Fedora or Ubuntu and try it from a live USB before installing. Both are reasonable options, and the one that works well with your hardware and feels comfortable to use is the better choice for you. You don't need to dual boot both of them.

Check Wi-Fi, sound, display output, and your editing software during your testing. If you decide to dual boot with Windows, back up your files first and read the installer options carefully before changing partitions.