video overlay

[BirdiesnBourbon]

Hi - I am looking to upgrade my YouTube videos and need some help! How do I put my video over an image to delete any dead space, customize and remove Zoom watermark. I have the image but cant get it right. I'm not looking for a virtual background as I want to use my actual background. When I try using filter, it does exactly the opposite of the desired outcome, picture covers up video. Any guidance here is appreciated.