Iphone came back from having screen mended now dont know what todo.

My IPhone was sent off to have the screen mended. I picked it up yesterday and it says I either need to Choose a Wifi Network or Connect to ITunes.

Wifi isn't an option as I'm at work so have just downloaded ITunes onto my computer but am unsure of what todo now as the screen just says

Connect to ITunes...its black with the Blue iTunes pic in the middle and the charge port picture.

Thanks