Additional furnishings and decorative elements add the finishing touches to your plans. Suitable 3D models can be found, for example, from these services:

Sketchfab
Free registration, partly free models in very good quality and various common file formats
https://sketchfab.com/3d-models

Trimble Inc® 3D Warehouse
free models in SKP format, own pCon.collection especially for users of the pCon.planner

There are also databases for 3D models on many different topics.
Download third-party models into your local file system and insert them into your planning by drag&drop or via the Media Browser (on the toolbar on the right-hand side of the pCon.planner).
An overview of which 3D formats you can import into the pCon.planner can be found here.