Question

I'm trying to get the sound to come through the computer and headphones if possible. I'm not sure if I can do that or not. Or if I have to just use headphones or speakers.

Answer 1

When using an audio interface you'll need to use the main output/headphone jacks on the interface for output.

This is covered here:

http://support.presonus.com/entries/21351334-Why-won-t-my-AudioBox-record-or-play-back-audio-

This is standard for every USB recording interface on the market, not just PreSonus gear.