This is not a crooked problem. You weren't square to the row of people. You should have moved to your right a bit.
So I figure you'll have to distort the perspective and hope for the best:
No you don't.
Your statement implies the assumption that your in-camera white balance is correct. But that is a false assumption in the majority of cases.
No, sorry, it'll need to be darker than that.
Or find different links, to photos that you like with more light in the background, similar to your photos.
Yes, truly, it shouldn't be too hard.
This is exactly the kind of challenge I'd recommend for somebody who's just learning about cloning. It'll test you, but it's achievable.