How to create a rudimentary "typing"/print mechanism (move a selection of grid tile along, and press one of 120 buttons to print image there)

Hi! I am doing a uni project, where I need to create a world that has a very basic pictographic “keyboard” and UI “print” area.

Please see diagram.

The “keyboard” would be an 11x11 grid of image buttons, that, when pressed, would print their image in a tile in another, larger grid. All I need is a mechanism to move a “selection” from one tile of the typing/printing area to the next, and print the image there. Also a way to reset it (no backspace, if much harder).
All I can think of right now is having all 121 images transparent in each display-area tile, and having the keyboard buttons linked to change opacity (not that I know how to do that either); what I really have no idea about is how to make a moving selection, so I don’t have to have one keyboard per display-area tile.

This is my final project for uni and I would be so grateful to anyone who could help me work out how to even start working out how to do this. I have basically no coding experience, but access to tutors that can code - however they will likely only know C# (if that).

The idea is that there would be two, facing each other. Ideally, there would be two displays per person, back to back, so the person can see what they are typing while it is also displayed to the person facing them, on the other side. But this is not essential.