Parameters, Properties and Entity Info

To change a selection's settings: Parameters

Select something and open Parameters. You get that kind's settings, plus a Level field. With nothing selected and a tool armed, the same row shows the settings the next thing you draw will take. With neither, it tells you to arm a tool or select something. It opens itself the first time you select something.

To see or set construction data: Properties

Select one object and open Properties. Door, window and wall types show their shared values here (Fire rating, Acoustic rating, Material, and Mark for walls), with a note that every item of that type shares one value; a door or window also has an Instance section with its own Mark. An object brought in from a file has an Imported section, shown as it came from the file.

To read facts about a selection: Entity Info

Entity Info lists the Type, Phase, Locked, Hidden, Layer, Collections, Linked file, Material (Unpainted when there's none) and Length of what you've selected. It also holds Follows ground and Drape selection on ground, which change the selection.