C++ in Xcode 4.1

So I'm starting a C++ class next week in college and I decided today to have a go at writing a simple program in Xcode (Just a Hello, World! one).
I went to "new file" in Xcode and chose C++ syntax highlighting and wrote it..

Now, I think it needs to be complied before it will run, and I don't know how to do that. I've tried lots of different things and googled around for a good while and couldn't get any answers.

So, what do I have to do to get this to run and/or compile?

 

Ah, project it is then , thanks

I don't see why it can't just compile from a file type I created though, it's annoying. When I chose the project option in the menu above I can see the run/compile options but they're greyed out and I can't use any of them.