First of all, welcome to the forums!
Your screenshot looks nice, and seems like a pretty good start to a game. However, a MMORPG is a very ambitious project to take on, and takes quite a lot of experience to set up and maintain. I would suggest that you work more on the gameplay within a single-player world, and once you feel good about that try to tackle multiplayer.
If you still want to code multiplayer now, here's a few plugins that would do the job well:
Barnski's Winsock Plugin is a good free plugin that can handle both TCP and UDP networking.
Multisync is another good plugin.
DarkNet costs money, but is a professional plugin with many features.
