Vanilla Debian or LMDE. Caveats are:
- that you dont intend to seriously game on it, and
- have at least 8GB RAM (for a smooth GNOME desktop experience).
Use system packages as much as you can and only use Flatpaks if you need the latest and greatest of a certain app (example being the LibreOffice suite for better document compatibility).
Learn how to backup your system with Timeshift and your data with Pika. You'll have a really wonderful system that you can will serve you well and at the same time be a good base to improve your Linux knowledge.
This is what worked for me when I first started. My workstation still runs Debian many years. Its rock solid and I have no reason to change to anything else.
My only regret its that I didn't move to Linux sooner. God luck on your journey.