Backdrop adjusts its size by default to fit your content you’ve placed within it. So naturally the height is going to depend on what you’ve placed within the tool. Without seeing that we can’t really offer any advice. If you’d like to share your live URL to the page in question, or your project file, with us we could better help guide you. Without either though we’d be just shooting in the dark.
Additionally your image in the middle is fairly tall and the image has some empty space around the actual graphic. You can edit this in your image editing software of choice to remove that extra, unnecessary space that is within the image itself.
Thanks for answering my question. I will look at the information you sent and work on those adjustments after dinner.
Another question. What size should the logo be when I adjust the parameters in my photo editing software? I have it a 72 dpi and I think 1000x1000 pixels square.
There’s no one right answer for something like this. It will depend on the situation, your wants and needs, and more. That said I can say that 1000 x 1000px is far too big for the spot you’ve got for your logo in this design. The logo in your design is currently displaying at less than 100 x 100 px.