I'm new. I've been trying to play the song 'I Stand Alone'. I can read tabs and I can get my guitar in drop C, I am just not getting the heavy distortion noise. I'm wondering how I should adjust my amp to achieve that? I have a Dean Markley K-20X. Is my amp is even capable of sounding like that?
The K20-X manual has a pretty thorough explanation of how to get overdriven sounds. http://www.deanmarkley.com/Info/LegacyAmps/Manuals/D1015.pdf
In brief, an amp like this has two stages of amplification: the first stage "preamp" feeds into the main amplification stage. If you turn up the level of preamp, then there will be some distortion in the preamp itself, and also you'll be putting a powerful signal into the main amp causing further distortion there.
Turn knobs marked "gain" or "overdrive" all the way up. Turn other volume knobs down to get the loudness you want. Once you've proved you can get heavy distortion, dial things back to find the tone you want.
Some amps won't distort at low volumes. If yours is like this, either just play loud, or consider getting a pedal to provide distortion.
Sometimes, in order to distort well an amp needs a stronger signal than your instrument can provide. In this case, consider getting a boost pedal, or since you're buying a pedal anyway, a distortion pedal.
I looked around for info about this amp and I found this picture of the amp:
Based on this picture it looks like the drive switch will give you some distortion, although I doubt it will be the amount you want.
This amp does not have the traditional gain knob so customizing the distortion would be hard. I would advise getting a better amp that can handle distortion better or getting a distortion pedal if you want more distortion.
EDIT: As suggested by Ulf Åkerstedt, try flipping the drive switch and adjusting the volume knob. It may up the distortion.