I'm trying to program in the following mixes:

PROG - MIX1:
ELEV->THRO (Ch2 -> Ch3)
Down -20%, Up +20%

PROG - MIX2:
AILE->THRO (Ch1 -> Ch3)
Left +20%, Up -20%

Maybe I'm having a brain fart, but I cannot seem to figure out how to get these setting in!! Any step by step would be greatly appreciated!!

It looks like you have the idea about what you want to do. Pages 53-55 in the 7C manual give you the mechanics of how you actually input the parameters for the mix: which switch, which channel is master, which channel is slave, and the amount the slave moves when you move the master.

I don't understand the down/up and left/up stuff! Do I move the stick that direction when I make the settings?

If you are making a mix with elevator as master, then you move the stick one way and you'll see one of the %-signs flash. Turn the dial to change that number. Move the stick to the other side and the other %-sign will flash. Turn the dial to set that number.

We don't know what you mean by the down/up, left/up stuff. The percentage of mix determines how the slave channel will mix with the master. If the servo moves the wrong way, just rotate the dial until the "+" becomes a "-" or vice-versa.

These two statements:
Down -20%, Up +20%
Left +20%, Up -20%

Do I move the stick Down, then set to -20%, then move it Up and set it to +20%? etc.

BTW, this is to mix the throttle with cyclic movement to compensate for drag on the blades to keep the altitude close to the same

Never mind, I figured it out - you have to move the master control to switch between the two settings.