Clash of clans networking.

Ok my question is that does anyone know a good networking tutorial that works close to the way as clash of clans? So basically when player plays then it creates a server by its self. Then when he wants to attack someone then it will join the other persons server.

IMO, The best possible solution for Networking in Unity (for beginners) is PUN.

Go to the asset store and search for Photon Unity Networking for more information. It gives you free 100 CCU, allows users to host and join games. This might help you achieve the functioning you want to achieve.