How to align the fields properly and change the background of the form?

How can I change the background color and make things side by side instead off doing straight down?

To make the fields show on one line, you have to shrink them and increase the form width (if needed):

Regarding form background, please check below, you can add an image as a background to a page and form in Form designer:

Let us know if you have any further questions.

Thank you!