Trying to replace an image

My site is http://www.mcfarlandcreativeworks.com and I’m trying to replace the clipboard/plant/coffee image with one of my own, or perhaps a carousel of images. I’m having trouble doing that and could use some advice.

I have WordPress 5.2.4 , Nimble Builder v1.9.4 + Customizr theme v4.1.45

I’m in the section Customing Content Picker, Pick a Section, About Us Sections. This is where I got the clipboard and text I’m currently using. The clipboard image has a plus sign in a circle on it. When I double-click that it says “Drag and drop or double-click the content that you want to insert here.” I am on a Mac, and have tried dragging a .png and a .jpg file onto this area but nothing changes. I have also tried dragging Image and “Image & Text Carousel” from the “Pick a module” bar on the left side, but nothing changes.

Help?

Thanks!

The page I need help with: [log in to see the link]