Construct 2 has a behavior called "Drag and Drop" which makes the object that has the property able to be dragged and dropped where ever you want. Simply start a new project, place an object on the visible area, give it the "Drag and Drop" behavior and hit run. You will be able to move the object around as desired. All that is left is to test if the location the object is set is correct or not. To make it return to it's previous location on failure, give the object local variables containing the x and y positions of it's start position and on failure, set the objects x and y = to the stored x and y.
There is a tutorial RPG-Inventory drag and drop. you can find it here:
It shows a more extensive answer to your question. I have not actually read through the tutorial but it appears to go over a little more than what I did.
There is a large collection of tutorials on this site to help people just getting started. To find the above tutorial, you could go to the Tutorials section and in the search box, type "drag and drop." I'm not sure how/where you looked for tutorials but this is how I found the tutorial reference for you.
Also, Construct has quite a few examples shipped with it. In many instances, you can find one which will show you how to use most of the functionality by creating a new project and scrolling through the list of templates.