Title says it all really. Its not got a USB port it has a Line out and im assuming that goes to the line in on my computer?

correct me if im wrong
It would be best if you sold the mixer and got an audio interface to record. Most softwares will let you mix "in the box" these days which keeps quality up.

If you dont have the cash to get new gear, simply run the record outs or a set of sub outs to the line in jack on your stock sound card.

Analog mixers are mostly useless in digital recording these days. With interfaces going down in price and quality going up they are basically replacing the mixing in studios.