Great news, James. Yes, your first Moodle can be called your "production" Moodle. Your second (and even third/fourth) can be called "experimental." If you desire (and your VPS has space) you can even make your second Moodle mirror your first. Then, before updating your production Moodle, update your experimental Moodle to make sure everything is fine, then update your production Moodle last.
I don't do this myself. Instead, I have MAMP Moodles for experimentation. I did install Moodle 3.11 and Moodle 4.0 on my server, anticipating change. Doing so let me discover that I needed to install sodium on my VPS.
I don't do this myself. Instead, I have MAMP Moodles for experimentation. I did install Moodle 3.11 and Moodle 4.0 on my server, anticipating change. Doing so let me discover that I needed to install sodium on my VPS.