Avery Theme Customizations

Hello,

I have the Avery theme and I would Like to make the following changes. Please tell me where I can find the exact locations for the current styling so I can make my own customizations in each of the following:

-Site Title (Where can I add or replace the current title image with my own similar custom image.
-Header Photo
-Replace or delete the current text below the Header as well as changing the color of the transparency.
-Change or delete the button.
-Change or add the menu items below the Site Title.

I want to keep most of the organization and styling of this theme and whatever else I need to do I think I could manage through the customizer. However, I have been unable to make the changes in the items listed above.

Thank you.

P.S I think it would be most helpful if there was documentation on each child theme listed in the GeneratePress Site Library so that GeneratePress users can work with these themes much easier.