iMovie for iPad 9th Gen will not let me select the video and start editing. What am I doing wrong?

I recorded a video on my 9th gen iPad in class and I would like to edit it; shorten it, remove the audio, do a voiceover, add transitions, speed up and slow down. I opened iMovie and selected Movie. When it brings up the list of my videos that are in my Photos app it will not let me select the video to edit. When I tap Select on the right side of the screen it does not function. When I tap Cancel in the top right corner it does not function. When I tap Media in the top left corner it does not function. I had to swipe up a force close the app. I was able to select the video to edit only one time, but at the bottom of the screen where it says Create Movie, it says 0 as if the video to edit had not been selected. The video itself is about 45 minutes long. I don’t know how to edit this video.