Amplitude Pro Theme Issues

Hello, can you help with the following? I am also relatively new to WordPress, so please excuse my inexperience.

1) The installation guide suggests importing the Demo Content but does not say where to put it. I do not use the same WordPress importer utility (I have WP All Import), so I have to provide a destination for the amplitude-sample-data.xml file and other attachments. Do they go into an existing file or must I create a new file?

2) I set up my homepage using the free version of Amplitude which placed the Amplitude logo in the Header where my Site Identity should go. I cannot get rid of it. I even tried uploading my own logo, hoping to over-write it, which did bot happen. My logo is a jpg image that scales incorrectly when going from full screen desktop to small mobile format and now I cannot get rid of my own logo either. In the Appearance>Header menu, selecting “Hide Image” does not hide the image even though it disappears from the customization menu (yes, I updated and republish the page which did not help). I even removed all images from the library, to no avail.

I have not hand-written HTML code in 20 years so don’t even know what files to look at even if I knew the proper syntax, so thanks in advance for your assistance.