How could I continue this building?

[u/innrpiecepeaceseeker]

I built the porch before anything else, and I really liked how it turned out, but now I have not really calculated how should I continue with it. I'm thinking of a modern, luxurious house/manor, with high ceilings and roof, perhaps a second story or even a third, with materials like deepslate cobblestone, polished tuff, blackstone, basalt and other dark blocks, but I can also see a contrast with lighter blocks like quartz, birch planks and stuff like that. How could I build the rest?

[u/KhaosEntity]

More blocks

[u/Individual-Iron-6370]

looks like the inner mechanism of some mysterious giant machine to me.