My video is not exporting on iMovie

I have a video made and I tried exporting it using quicktime, the bar shows up to load the transfer but then disappears and nothing happens, I have also tried exporting it normally, uploading it to youtube, and pretty much anything. I'm wondering if I/m doing anything wrong and/or if its the type of file the videos are, but I filmed them with a camera, iPhone, and my Macbook Pro. Note that this is also my first time using iMovie and I could have done something wrong along the way of making the video or I just have been clicking the wrong thing.

Please help me 😀

Thanks,

A confused iMovie User