Need help spawning actors to specific locations randomly

Im trying to create platforms that will spawn next to each other from a central point on the X and Y axis. I want them to spawn randomly next to each other eventually surrounding the original central point. I have three actors that I am trying to get this to work with but after multiple attempts Ive just cant figure out how to do it.

This is an example of what im trying to so simplified as much as possible. The square’s should keep growing, eventually becoming huge.

The central point would be the sphere.

Then when the player presses F the tiles should spawn randomly at these four locations.

When the player presses F again more tiles should spawn however instead of going where the firstly spawned tiles, they will attach to the spawned tiles in random order looking roughly like this.

When the player would press F again it would grown again adding another row of tiles around the outside. The player would be able to spawn as many as they want.
I’ve been trying multiple different ways and I have no clue how to do it.

Thanks.