I’m using Tailscale and you can find my experience installing it it here: Tailscale for remote connection to the NAS
My humble home router/modem isn’t capable to run a VPN by itself, but tailscale is working great so far. 
It’s really not that difficult, basically install Tailscale in your NAS (low/medium difficulty), install it on your other device(s) (low difficulty), sign up with an account (like google, apple or microsoft) and everything is connected and working. No need to touch any setting.
Have a nice day.