Hey, Sam!
Please take a look at the following function to collapse/expand elements https://www.wix.com/corvid/reference/$w.CollapsedMixin.html .
Also, check this example that you can use https://www.wix.com/corvid/example/collapse-elements .
Please keep in mind that when an element on your page is collapsed, the elements below it on the page can either shift up the page or stay where they are. This behavior is controlled by the size of the gap between each element and the element directly above it.
Check the rules for collapsing and expanding elements here https://support.wix.com/en/article/corvid-how-page-layout-is-affected-when-elements-change-size .