Footer Widgets And Copyright Text
Footer consist of 2 areas.
Widget area that can keep up to 4 active sidebars.
You can customize the width of each footer sidebar in the Appearance > Customize > Footer. For example you may want only 2 sidebars, one of 2/3 width and the other one will keep the 1/3 width. That mean you need to disable 2 extra sidebars. To do that go to Appearance > Widgets and just clear two of footer sidebars, so they will be empty. Others two need to have al least one widget each to be visible on the site front-end.
Bottom line with random information (usually copyright).
This text can be changes in Appearance > Customize > Footer.