Selfhosted

I run a load of containers on a NAS, and reverse proxy them through synology's inbuilt reverse proxy settings.

Essentially, I'd like to harden my security, and not really sure how best to do it.

Seeing people recommend nginx proxy manager, I've tried to set this up but never managed to get the certificates to work from letsencrypt ("internal server error" when trying to get one). When I finally got it working a while ago (I think I imported a cert), any proxy I tried to setup just sent me to the Synology login page.

I've tried to setup the VPN that comes with Synology (DSM 7+), but I must have set it up using the local IP address. It only works when I'm on my LAN, and not from an external network. Which is kind of the point, lol. I would like to use VPN to access the home network when out and about.

I've set random, long, unique passwords for everything I want to access, but I am guessing this is not the most secure, after seeing so many people use and recommend vpns.

I have tailscale, which is great for ssh-ing onto my Nas from the outside world. But to access my services, is a VPN the best way to do it? And can it be done entirely myself, or does it require paying for a service?

I've looked at authentic - pretty confusing at the outset, and Isee few evenings of reading guides ahead of me before I get that working. Is that worth setting up?

Does anyone have any advice/guides/resources that might help?