Can you use the built in unity network on the free version of unity3d?
you sure can! here’s the link! http://unity3d.com/unity/licenses
Nice so could it make pvp 1 vs 1 and 2 vs 2 multiplayer online game modes?
As long as the programmer can do it.
Although you would probably have to buy a dedicated server of some sort. I would recommend getting one as close to the programmer as possible. Unless the company can host it where they are at.
Using the built in unity network it has to be your IP address on your computer or the unity one?
Sorry, I don’t understand the question. 
Have you tried the resources page? here’s a link. That download could probably explain it better than I could.
http://unity3d.com/support/resources/example-projects/networking-example
I’m asking if I have to run the server on my computer for the unity netwok
bump
I think either on your pc or buying seperet windows pc and setingup a server there.
Does Unibill work well with Unity Free version? Sorry if my question is stupid because I’m really interesting with Unibill and want to know clearly before I buy this one.