You're almost done!
The last tracks on this session are the keyboards, an acoustic guitar, and a stereo track with two electric guitar tracks. These don't need any processing, but if you'd like to play with compressing, EQing, or whatever, it's up to you. Just because this session's recording style didn't need it, that doesn't mean you can't try it out, and it doesn't mean your next session won't!
If you've soloed any of the rhythm tracks, bring them out of solo by clicking the "S" buttons again. Blend in the keys so that the vocals and keys are similar in volume. Then bring up the acoustic and electric guitars to accent them - they shouldn't overpower the mix, as the vocals and keys should be more prominent.
How does it sound?
Play around with the blending; move the faders on each channels however you wish to get the mix that sounds best to your ears.
To finish your mixing session, it's time to bounce it to track. Click on File, then Bounce, then To Track. Select that you'd like it to be bounced down into 16 bit, 44.1 khz audio quality - which is CD-quality (the audio files in this session, like most, are 24-bit; you can't play those in a standard CD player). Click OK, and your file will bounce to one stereo file.
Congratulations! You've just mixed your first song!
Remember, every situation is different; using this guide, you'll have a good start for when you go in to mix your next project using Pro Tools.