[Help Request] I *think* what I want is a VPN but I'm not sure.

Local Setup: Proxmox server hosting a bunch of VM's; all accessable internally via either hostname or NGINX reverse proxy (I think that's what its called). PFSense handles all network "stuff" (DHCP, NTP, which hosts are allowed internet access etc). Everything is connected in a manner of WAN > PFSense > LAN / local Wi-Fi. Nothing has direct access to the internet nor is anything DMZ'd.

Goal: To be able to securely access services on my internal network from outside locations (Cellular Data; public wi-fi etc). I do not want the general public to be able to do the same so I do not believe port-forwarding is what I'm looking for.

Basically what think I want is to have my phone / laptop (or whatever) connect to PFSense and think it's part of my LAN in terms of usability. If http://hostnameA brings me to my security system NVR while I'm at home, I'd like it to do the same while I'm away. It must also pass the "wife test" in terms of usability. There are a few Android VPN apps that (as far as I can tell) are simply "click this profile name and you're connected" so that aspect should be fine.

The Problem: I'm unsure if this is A) the best way to go about it and B) most of the how-to / guides I can dig up are either quite dated or focus on using a VPN provider not on being a VPN.