Everyone else is telling you to stay local, which is great advice, as far as it goes. But you said you want to host your website publicly available, so i’d recommend getting a cheap vps and starting there. It’s not on your network, so if you screw up with security, worst case is you start again from scratch. I’d recommend the cheapest virmach VM you can get, with Debian or Ubuntu, if you like snaps.
First things first, set up ssh with key based logins, with a passphrase on a non standard port (doesn’t provide security, but it will keep your logs from getting innundated immediately). Install UFW, and block all incoming traffic, allow all outgoing traffic, and limit traffic to your ssh port. Install docker and add your user to the docker group. Start learning how to use docker, compose, and as your first container, set up duplicati to back up your docker directory (including all your volumes, which I would store as folders inside your docker directory) somewhere else. I’d set it up to run every evening after you go to bed, and i’d also set a cron script to bring down all your containers before you back up, then bring them back up. Just in case.