Need help with averaging every other cell column and leaving out the #DIV/0!

I'm putting together a page that transfers %'s from one sheet to another, then on the new sheet, i need to get the average percentage from every other column cell and ignore any #DIV/0! that might copy over from lack of info.
I am an excel beginner and using a formula that looks like this =AVERAGE(C3,E3,G3,I3,K3,M3,O3,Q3,S3,U3,W3,Y3) to get the average in cell AA, but ofcourse if a #DIV/0! is involved it wont work. whats the best way to write the formula so that I can get the result i'm looking for? Any help is appreciated!

I found a previous thread that had a formula I could use, thank your guys for this forum.

=LOOKUP(9.99999999999999E+307,CHOOSE({1,2},0,AVERAGE(IF(ISNUMBER(C2:Y2)*(MOD(COLUMN(C2:Y2),2)=1),C2:Y2))))