I am looking to get started and completely new to wordpress

I am looking to get started and completely new to wordpress and even more so to the plugins.

Firstly, UI am planning to create a multisite social networking portal with memberships and such like along with some ability to oist classified ads and sell tickets for evens.

Firstly do I have to subscribe to wordpress (Like a Pro?) and then use these plugins on top of that?

Is there a basic tutorial that helps some one get started ?