Part 1: How To Create And Save Global Sections.
Navigate to the builder
Click on the + icon on the top left, and add a section
Edit the section as needed by adding your columns, rows, and elements.
Navigate back to Section by clicking on the layers icon, then on the section, then on the 3 dots, then on Save Section
Name the section and save it as a global section
Part 2: How To Add Your Previously Saved Global Section
Click on the + icon to add the Global section you just saved
Click, drag, and drop the global section where you need it
Save
Note: The global section would need to be added to each page you want it to be. Any update to that section will update the global section for all pages.