Hello
Durk1.
There are many different ways to master a song.
And many people master tracks, in many different ways.
To answer both your questions.....
Yes,
GingkathFox is right. You can master your sound tracks in Lmms.
Or if you want, you can master your music, in a free audio editting software called
Audacity.
If you plan to use
audacity for mastering, you can either export all the tracks of your song
and bring them all in, into audacity.
Or, if you want, you could export your entire track, bring it into audacity and use audacity's effects etc. to master your music track.
We have a few mastering tutorials, in the
Tutorials section of the forum.
Here is a link to two such tuts, to use as examples.
The Complete Noob's Guide to Mastering:
https://lmms.io/forum/viewtopic.php?f=3&t=5615
Mastering Techniques!:
https://lmms.io/forum/viewtopic.php?f=3&t=50
And check these two below, that help explain what
equalizers,
compressors and
limiters, do for mastering.
Improving LMMS (Chapter 1: Mixing tools!) Part 1: Equalizers:
https://lmms.io/forum/viewtopic.php?f=3&t=688
Improving LMMS (Chapter 1: Mixing tools) Part 2: Compressors:
https://lmms.io/forum/viewtopic.php?f=3&t=690
And don't forget, as I said before, there are many different ways to master a track.
And everyone has their own different idealogy, on how to master songs.