Hi there!
There is a couple of ways how you can do that.
In my previous profession, I preferred to work with point clouds rather than the 3D models from RC. I exported the point cloud from RC and created a simplified model in a BIM software. The software was then able to create floor plans and cross-sections from the model automatically.
Another way is to create an ortho projection in RealityCapture. Export the ortho projection to AutoCad and vectorized it there. This might be easier than making a BIM model. We have an FAQ article about ortho projections if you choose this way here.
Jakub