Os X, Tracktion W/ Motu 896, live audio w/ samples Options

[luemob]

I wanted advice on how to record live guitar and bass while playing to a sampled drum loop, I can play live audio with one track, just haven't tried it with two pieces of audio at the same time. The signal wave recording onto tracktion does look weak, not alot of volume going into it so I was wondering if I need to go into my system preference to make the adjustment.....also I wanted get some tips on how to create breaks or fills using the same sampled drum loop ( i know its general ) but any advice would help me out...