Hey Afrokid, welcome to GameCore.
What a good time to find it =). We are just finishing up a new release with a host of new features. The good news is there is a ton of resource information. Just be mindful that with our new release upcoming some of the information may be out-of-date. Just comeback to the forums and ask anything, someone should be able to help. Okay the info you wanted:
http://gamecore3d.com/docs/ - The documentation for the engine
http://gamecore3d.com/docs/videotutorials - some basic video tutorials
http://www.youtube.com/user/GameCore3d - This is our youtube channel if you scroll down the list of videos on the right side you will come to the video tutorial section, 17 videos in all I think
Vibe2K also has a real nice course, check the forum for info
Okay so about the RTS... (What follows is just my opinion and not the official position of GameCore =P). Since you know your good at modeling and animation already I would start with a basic gameplay prototype. Like 3 unit types - ball, box, and (the dreaded) pyramid. Start with small milestones and just keep adding functionality. Get them moving to where you click, have them "build" a structure, ect. Find a manageable pace and keep at it.
Good luck and happy building