Creating a Drag and Drop game

Hey I'm adri and I'm creating build your town game with an editor system that you can hold for a few seconds and then you can move that object, but using a grid, like you can do it in Clash of clans game. I'm new programming, and I'm using a Raycast system to detect the item I'm selecting, but more of here, I don't know how to continue with that system. I'm using c#. Can you help me doing that?
Thanks, Adri.