HELP ME!!!!! Music Creator LE

I just purchased both a usb cable for a direct line for the guitar and the mic. I am having trouble getting playback in my headphones when I'm trying to record another track (i.e. vocal). And, I don't know anything about sound cards or inputs/outputs. I'm confused.

What I want to be able to do is record my guitar (which I can do since I don't need playback since it's first track). Then, I want to record a vocal (or something else), and have the guitar on playback in my headphones. Remember, the usb still has a plug in (to record the vocal) and for some reason, the sound gets turned off when the usb thing is plugged in. So, I must need to change inputs and outputs but I've tried all the options under the tracks. I think I need to add some other options because nothing is working.

Thanks for any help you can give me. I really want to record and don't want to have to give up again and send this stuff back.

Amy

What Greg says is correct.

The only USB "things" that we recommend are the USB interfaces such as the ones by M-audio, Focusrite and others that make the dedicated music recording interfaces. The better music stores with pro audio departments can certainly assist you in choosing the right one for you. They allow simultaneous record and playback of multiple tracks, have low latency (delays that you can not hear), and are surprisingly affordable. They all have headphone outs on them that allow you to hear the playback and recording as it happens.