FOSS gamedev and creative worlds

Hey everyone! I'm relitivley new but already got a 15 block mansion up and going, I'm trying to finish it so I can creat a server but have NO idea what to do with the second floor, the second floor already has a lava fountain, the first floor has several water fountains and a bedroom and stairs a library and a kitchen...the top floor is going to be a pool deck area, i need ideas! and maybe someone who would be willing to work with me to finish it?

Make a Fireplace example:

Im new to minetest or any minecraftalike games in general but i think ive got the hang of this now. I have learned the basics and some advanced tricks and if you still want some ideas or someone to help im available