do i make a VPN connection with airport extreme?

Airport firmware does not include a VPN server but if all you want to do is forward the ports to a VPN server on your local network you need to ensure iCloud Back to my Mac is disabled both on the router and the Mac running VPN.

https://discussions.apple.com/thread/2357772

Alternatively, you could just go for a VPN provider, quite a few of them exist.