inside of the Onepager Builder the layout is based on a grid. This means you have a to select parts of the page in a square grid pattern in order to build your onepager with a variety of Interactive and Non-Interactive sections.
If you decide you want to move a grid section to another part of page you can use the Swap feature or you can Redraw the section again onto the page.
Once you have clicked the Redraw button inside of the right panel that opens up after you edit a section. The section be removed from the page and the space it filled will be free to add new sections too.
Once you select a new area for a section you will have the option to select a Redrawable Section if you have any that you have chosen to redraw. You can select a Redrawable section or choose to start with a new section.
You can also clean up any unused redrawable sections by deleting them if you are not using them.