Hi Belinda!
You want to look into ARIA w JavaScript. There are a few little things you can add to make single page app designs accessible for screen readers that can also work for what you’re referencing.
We will cover this in Advanced JS Topics, but here is a quick primer:
Single Page Apps – ARIA live content regions – https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/ARIA_Live_Regions
Basic Show Hide – ARIA hidden – https://www.paciellogroup.com/blog/2012/05/html5-accessibility-chops-hidden-and-aria-hidden/
Hope that helps!