Depending on the drawing, you can start to place the doors and windows into the external wall of the layout [i.e., Creating door and Windows in 2D]. Once all the doors and windows are done placing then select the 3D modeling [by selecting the workspace switching].
Now follow the below-given steps and finish your drawing.
1. View controls and Visual Style controls
This view control and visual Style controls provide access to standard and custom view, and 3D projection as to the visual style controls.
Now that the plan has been converted to 3D modeling select the visual style controls [below the Menu bar of the workspace] then select the wireframe clicking the right side of the mouse.
2. Add layer for 3D door and windows
Select the layer and click on layer properties [ Menu bar> layers> layer properties] and add layers for 3D doors and windows [ edit layers as desired].
Now that the layer has been selected change the workspace to drafting and annotation [by clicking the workspace switching] and draw a solid object around the edge of the doors and windows using the polyline command/rectangle command. [ change the view to 3D modeling].
3. Extrude/press pull command
Now select the object for the doors and windows and click on the extrude/press pull command [enter dimension as required].
4. 3D moves
Select the 3D doors and windows and mention the height for displacement as per the wall height [3D move>select object>Displacement> specify height with x, y, z ordinates].
5. Solid Editing
Solid editing is a toolbar place in the workspace of the menu bar. Solid editing has tools namely Extract edges, slice, union, subtract, intersect etc.