Welcome to Deezire Online Forums and the C&C modding community.
XCC Mixer is available at
http://xccu.sourceforge.net , you should also get XCC Mix Editor while you are there.
The first step in C&C modding is getting familiar with the art(md).ini and rules(md).ini files.
If you have further questions feel free to post here.
I'm not much of a motivational speeker...
It may seem overwhelming at first and some people never really get the hang of it, but if you play mods like Deezire's then you will know that it's possible. For most people, it gets easier with time.
You should read
Creating new RA2/YR .MIX files
Two good places to look for cameos are:
You can go to my page:
Kravvitz's Cameos
Renegade also makes good RA2/YR Cameos:
Renegade's Cameos On Damand
The Best RA2/YR Modding Resource Sites are:
( That was my stock reply to new modders )