I and few people made our own modding server which is focus mostly on KW/RA3 modding and contains some guides and tools for beginners,

this server may not have the best of the KW's elite modders but it does have some people who been around at the modding scene for quite some time, so if you need some help or want to know some of the ropes for modding it may be a nice place to start at

C&C modding facility
just another C&C modding server but without the toxin =D

https://discord.gg/5ZXWhVsWds

Cheers~