Fooling around in Unity 6.3

Hello. Given Unity 6.3 and 3 isometric blocks (attached). The following needs to be done:
1) Generate a 3*3 tilemap chunk with code, each chunk containing 16*16 tiles, use any two blocks randomly, all must be on the same plane.

2) In random places, add several obstacles made from the same blocks, as a second floor.

3) You can use any cube as a character, the character must move (wsad) on the plane, collide with obstacles, jump on them, and fall from them.

4) When moving, replace the tile on which the character is located with a third cube from the set, so it is visually clear which tile the character is on.

5) When clicking the cursor on a tile, the character moves there, not teleporting, but moving towards the tile.

Attached is an example of one chunk, I think the essence is clear.

Please do not use AI, I need clean and understandable code; I can ruin it myself instead of chatgpt.