You can upload an image, or select from your library, using the 'Image' selector at the top of the section settings.
Using the 'Layout' tab, you can choose to place your image on either the left or the right of the text.
You can add an (optional) heading, which will show above the 'Text' box below.
In the 'Text' box you can add text, which can include bold and italic using the 'Text' box.
You can add an optional button to your image by filling in both the 'Button label', and the 'Button link'. The button itself won't show until both of these fields have been filled out.
The color of the button is set in the 'Colors' section of your 'General settings', under the 'Buttons' header