I'd like to make an open world game were people can do anything. Multiple difernt story lines, jobs, missions, ect. I don't have unity or have ever used it. I'm just checking it out right now.
You can make whatever you want with Unity. Given unlimited time, naturally. What you're describing there has thousands of hours of work in it. But don't let me discourage you! You really can make anything with Unity, you just might have to aim a little lower to begin with.