I‘m more interested in geometric structures / architecture, so the sculpt mode isn‘t very useful as I realized today (after watching a video about it). This is

I‘m more interested in geometric structures / architecture, so the sculpt mode isn‘t very useful as I realized today (after watching a video about it). This is all about taking a sphere with lots of vertices and pushing them around. I‘m looking for a way to fill gaps in meshes and deal with relative simple low-poly geometries. Ideally with semantics (a thing is placed on a floor). What should I use for that? Are there plugins thatbpush Blender towards CAD (which I know nothing about)?