So I have two questions here, let's say I create an application with XD and want to add a store , online store how do I go about it
Secondly after I create an app with XD is it possible for me to upload to the app store or play store, if yes could someone please direct on how to do so, if no this should be made possible.
You don't create an app with XD.
XD is a design tool for designing apps, websites, etc. You would then need someone to code the app to get a functioning app.
Think of it like an architect. Architects use apps to design buildings, but those apps don't create the actual physical building. Construction workers must then build those buildings according to the architect's designs.