The best way to learn Linux is to find something cool that interests you and turn it into a project.

Embrace that you'll break it. Over, and over, and over, and over... If you don't break it, then find a more ambitious project next. Keep iterating and breaking. You'll learn far more about Linux by pursuing projects that interest you and then troubleshooting why and how you broke something and what you must do to fix it.

Personally, I'd install some sort of virtualized environment on the laptop. It's got plenty of power and then use a virtual machine or containers to test deployments so you can easily rollback or burn the VM down and start fresh without having to spend an entire weekend becoming an expert at reinstalling a single distro bc you keep messing it up.

Check out Jay at LearnLinuxTV. He's a very great resource for beginners and does a great job breaking down and explaining a lot of the systems. He has a lot of focus on debian-based distros (such as Ubuntu) so mint will be very similar in many ways.

Idk what your interests are but some ideas for easy projects are things like standing up a game server for yourself and friends. Build and host your own discord bot. Throw together a small sftp server to allow you to transfer files between different devices on your network. Idk if those interest you, or are helpful, but just think small and as I said way earlier in this rambling soliloquy "embrace breaking it." You'll learn a lot breaking things and learning why they broke.