Can my friends join me through VPN as they would be in my lan network? I would like to create some game servers in my house but unfortunately my IPS don't want to assign me a static public ip and open ports to my router. My question is can my friends see me (as they would be in my lan network) and connect to my game server through VPN? I have Oracle Free Tier vps and I could create OpenVPN server to let them join it. I know there are soulutions like Hamachi but I would to create my own server mainly due to high ping in and members limit.

Yes. Check out Tailscale, which does VPN - but in a meshed fashion, so that after talking to a central server for coordination, each of your machines talk directly.

Basically, you and all your friends should install this on your gaming machines, plus install it on your gaming server. It will assign all machines (workstations + servers) a new IP which runs on an overlay (VPN) network, and you'll be done.

You'll need to configure each machine to connect to the same VPN.

You will then be able to run your server on your local (home) Lan or on a VPS with some hosting provider. Either way, it will work.