I made a movie on imovie and want to put it on after effects to add effects to it. Whenever I tried, it said that it wasn't compatible. Is there a way to add your imovie project to after effects?
You also might wish to visit the apple.com discussion forums for iMovie. Exporting from iMovie is non-intuitive, you use Share. but you need to understand what formats and codecs AE prefers so read up on Todd's link. If you're just starting into this, export out of iMovie at less than full HD until you understand the limits of your patience for previewing your effects editing and then rendering out of AE.
Plus, you will need to understand how to get back to iMovie so you can use Share to upload or distribute your work. It's complicated.