Most people don’t realise, yet so obvious

I’d suggest to start with ubuntu. I’d the distro that has the most guides/resources available.

Personally, I prefer xubuntu. Which is ubuntu, but with a slimmed down UI.

I’ve heard good things about https://www.linuxmint.com/, maybe read about that one too.

To get started, I always use Rufus (https://rufus.ie/en/) which downloads the required files, and makes a bootable USB flash drive.