I'm new to self hosting. How do I monitor security?

I'm not great with Docker or networking, so when I picked up an n100 mini pc for self hosting I installed Ubuntu and Tipi to get started.

I used Tipi to install Immich and forwarded my ports, then setup cloudflare tunneling to expose it to the internet. Currently I'm migrating from Google Photos.

But since I'm new to this I'm worried about exposing Immich to the internet without really knowing what I'm doing. Any suggestions on ways to monitor my setup to make sure nothing goes wrong or gets hacked? Ideally any application suggestions would come from the Tipi app store but I'm willing to learn if there's no other option. Thanks!