Change site logo,Title and Favicon

Go to Dashboard >> Appearance >> Customize >> Site Identity.
Click on Select Logo for upload or change site logo from existing logo.
Enter Site Title and Tagline.
Check box option about site title and tagline display.
Click on Select Image for upload favicon.
Click on Save & Publish button.

Configure Background Color

Go to Dashboard >> Appearance >> Customize >> Colors.
Choose the color for site background from Background Color option.
Click on Save & Publish button.
Configure Background Image
Go to Dashboard >> Appearance  >> Customize >> Background Image.
Click on Select Image button.
Upload or choose an image for website background.
Click on Save & Publish button.