I need help with the volume of the amp?

[KabaNah1]

Hi everyone. Sorry im new at this, dont really know many technical terms, but i will do my best.
So i have an amplifier, and i connect it to the soundcard, and ive been using sound forge 7 to do some recording. The problem is, i dont know how to control the bass/treble/volume of the amp, i mean, i know how to but it never comes out right on the recording. either the backing is too loud, or my voice is too loud. someone told me i need a mixer, but i dont have one. I really need some wisdom here Thank you so much

 

[moresound]

Well a mixer would be nice! It would give you more control over your mix if you had it in line.

 

[KabaNah1]

Is there a program i could use? a mixing program? ty