I would like to make favorites page on my app in which people can click a star next to an item on one page and then it get saved to a favorites page. Can someone help me on how to set this up. Would this be an if statement within a formula? Would this be setup through app or page variables?
You have to save it to a client-side database / local storage. You can store things in a data/ app variable but these, as far a I know, will only remember information as long as the app is still running.
When the star is pressed, you should use create record and input what item/information you want to be saved, including an ID. Text is easier to save than pictures. On your favorite page you are then able to get/show the information you have saved in your client-side database. You can also then use delete record should you wish to remove the item from the page again.