For use to connect to home network drives, I've used ZeroTier https://www.zerotier.com/. I've never had an external IP for home internet, so I always ran in headaches trying to do a home VPN to channel my internet traffic while I'm out and about (and that's why I use a VPN on a VPS for that).
I can also recommend OpenVPN's virtual appliances: https://openvpn.net/virtual-appliances/ They work out-of-the-box and come with a web UI for configuration, if that's your thing.
That said, I've moved on to Wireguard lately and will be unlikely to use OpenVPN for personal VPN networks in the future.
Give wireguard a try. Had the same experience with OpenVPN, yet got wireguard to work pretty much immediately.
It works really good and is super easy to set up, this was also my first time setting up home VPN, so I didn't have any previous experience, and I still got it working easily.
Then you simply copy the .ovpn file from your server (the firewall) to your clients (phones, laptops), and open the file with an OpenVPN client on each device. It contains all info needed for them to connect to your new server.
Works very well for me.
https://github.com/rajannpatel/Pi-Hole-PiVPN-on-Google-Compu...
That being said I pay the $40 a year for PIA since I torrent all my movies and tv shows. I use that VPN 99% of the time.