The Short Answer:
Wade through the promo material that's loaded into the free version
Click the + Video button at the top to add the video you want to crop
Click the Crop button that appears below your video
Check the "Enable Crop" button and choose a preset aspect ratio (for YouTube, you'll probably want 16:9)
Use the cropping rectangle to define the area of your video you want to keep
Finally, click the Run button to process your video -- the new file will be saved and VideoProc will open the folder where it saved it
First, you have to understand that "trimming" a video is shortening its length, while cropping a video keeps the whole length of the video but eliminates a portion of each frame. Cropping a video is like cropping a photo, whereas trimming a video is more like cutting off the start or end of a film reel.
If you want more options or a deeper explanation, I recommend this article
, which is what pointed me to Video Proc.
I use Video Proc to crop screen recordings from my phone. I first found it when I was making a little promotional video
for Biden Time
, the Inauguration Day "Advent" calendar app I created with three friends.