Programming an isometric (top down) grid

Hello everyone!

  I am fairly new to programming, and have a question about how to go about programming a grid to use for a puzzle game.  I need the grid to be able to

• store tiles

• move tiles by touch to unoccupied space (which im assuming would be best kept track of by an empty game object

• build and layout itself dynamically after grabbing screen dimensions (this is to ensure compatibility with the numerous mobile screen dimensions. Im not sure if there is a certain/standard way to do this, or if Unity already has the capacity to do this, which i doubt, or if it is best to just grab screen dimensions and place the grid according to the results

• be able to increase/decrease grid size in the editor (which im sure can be done by using a variable to store the desired width and height)

  any sort of direction on the logic and/or proper way to program a grid for a mobile device would be greatly appreciated. I don't want to start getting my hands dirty with this until i know i am headed in the right direction. Again, any guidance is greatly appreciated!

  Have a great day!