What kind of help are you looking for? Information on setting up objectives? Invasion is the most complex of all game types, and even if you get the game to actually function like it should, balancing the map to be challenging and fun for both sides is very difficult. In my experience it takes a lot of play testing and trial and error. I have made a few invasion maps that work, but when I played them with a group, the balance was way off or there was an unforeseen problem in the progression, so I have never posted them up on forge hub. There are several really good invasion guides on this forum and other places around the interwebs. Just do a search and make sure you study up these guides first because invasion design is very complex and takes patience. Once you get something together, try to get your friends to play it with you and see how it plays or submit it to the testers guild. I hope this helps, good luck to you.
Reach Forge Tutorials Ep 3: Invasion Part 1/2‏ - YouTube Reach Forge Tutorials Ep 3: Invasion Part 2/2‏ - YouTube these are the vids i used when i learned how to do invasion