How to make Warped Continuity? (Continuity but with more features)

I am trying to make a game based on the puzzle game Continuity.
https://www.google.com/search?rlz=1.....0....1..gws-wiz.......0i71j0i67.S-bipWgvfVk

Basically the game has some similarities to a 15 puzzle where you can move a tile adjacent to the open spot, to the open spot, but each tile is a screen with blocks in it. The player is in one of the screens, and the exit door is in one of the screens.

Todo: I am currently trying to make templates for the levels, 2x2, 2x3, 3x3. Starting with a 2x2 level, I need to make white outlines for all 4 (potential screens). I plan to make each screen 12x15 blocks in size. I need to establish that the player can only move between the screens if their border tiles match (same block or no block down the line of 12 or 15 blocks). I need two modes, one where the camera zooms in on the character and it can move and jump, and another where the camera zooms out and the player can move the screens around.

Can anyone explain how to do my todo, mainly defining the borders between screens with a white outline and the player being able to move the screens around with the arrow keys?

Unity experience: I have used the console. I made the main menu and instructions screens with buttons that link to each other. I have purchased a black and white asset from the asset store and used it to make a character that can run, jump, and collide with blocks.

Thanks,
Sam