@Tessa_learner1 For directly reading the value and populating the same in the cq:dialog, it is feasible with the cq:design i.e. if configured in the design dialog via something like ${not empty cqDesign.title? cqDesign.title : ' '}
But for populating it from the page properties, you can try via the touch ui listeners
Reference: https://aemsimplifiedbynikhil.wordpress.com/2018/07/30/touchui-dialog-listeners-aem-6-3/
Thanks