[2023] Any block like the wooden railing for the floor?

Indeed. The 'bars' shape is sort of a classic go-to (they used to be exclusively iron bars). But there are a zillion different block shapes now, and you can generally rotate them however you want to work as a wall, floor, or ceiling. Use "Advanced Rotation" to try every possible angle. In my most recent base, I've used a shape originally designed as a metal pipe railing (edit: Catwalk V2 Rail Only Single Double End), rotated to the bottom of the voxel.