First of all, here's a website where you can find distros of all kinds: https://distrowatch.com/

Find a Ubuntu-based distro, ideally one based on an Ubuntu LTS version. The main advantage of an Ubuntu-based distro is that most people start out with an Ubuntu-based distro, usually Ubuntu or Linux Mint, so most guides, especially beginner guides, are tailored towards Ubuntu. In terms of what actual distros to pick, the Ubuntu family of distros tends to tailor their particular distro with a particular desktop environment (DE). Not all distros do this. For example, Debian and most Arch-based distros give you an option of picking which DE you want installed on the OS.

Here's Ubuntu-based distros organized by DE:

GNOME:

Ubuntu, Pop_OS (modified version of GNOME), Zorin OS (modified version of GNOME)

KDE:

Kubuntu

Cinnamon:

Linux Mint (Cinnamon version)

Xfce:

Xubuntu

Mate:

Linux Mint (Mate version)

LXQt:

Lubuntu

In terms of which DE to choose, it's honestly personal preference in the end. If you want to test out DEs, the easiest way is to find a distro that offers DE options in its installation like Debian and EndeavourOS and create VMs for each DE you want to test-drive.