Need "VPN" implementation in Android Studio?

Question

Android

I want to implement applications for Android like Hamachi and it appeared how to make it so that, for example, when a button is pressed, a server is generated, a password is generated or the connection data is taken from ready-made options, sent to the server and stored in a temporary database.
Like this?
Everything is very simple (no)
For example, there is a client that creates a server and connection data is sent to the server so that another client can connect that connects to the server to receive all possible servers
. It turns out such a scheme
client1-server-client2
client2-server-client1

And now what is the essence of the question is it possible to release all this so that it is not necessary to open ports and so that it does not work on a VPN?
Or is it still easier to do it on a VPN?
(If there are any questions, I'm ready to answer)
And from what version of android is it possible to do this?