You can find on the section's top right an option to access the section settings. In the settings, you will be able to modify the section ID, duplicate, copy, delete, hide, and cut a section. You can move your sections up and down with the arrow shown in the picture below.

Every section has a section ID, which is important because if changes need to be done manually you are able to use it by using its section ID.

If you need to modify a CSS property of your section using custom code, check the article below.

You can hide a section completely by unchecking the option "Show Section".