In the multitrack window you can adjust the both the vocal track and backing track volumes.

As for the voice 'not inside' the music, you'll have to play around with Delay Effects -> Studio Reverb, and Filters -> Equalizer (graphic or parametric). The trick is to match the difference in tonal signature and acoustic space of your vocal and their backing track. The difference is due to hardware (mic, preamp etc) and the physical recording space.

The reverb is insanely complex so you just use the provided settings and only tweak the one which match the closest. For the equalization you may add more presence (boost 1k-5kHz region). Additionally if your mic is not good you may even use dynamics processing to suppress noise and rumble, and even remove irritating sibilance (sharp "S"s).