Try Windows>Recently closed docks.
If they aren't there, don't panic
With "Windows>Dockable dialog" you can recreate any of these windows, the difficulty for beginners being to arrange them in "docks" (ie, make them share a desktop window). It's not that hard once you grasp that like in Firefox or Chrome, you have to drag the tabs inside the windows and not the title bars. Drop areas include the side of another window (lits up in blue when you are over it), the "drop anything here" area under the tool box, or the row of tabs (your dialog is then added as a tab).
To reset the windows to installation settings: "Edit>Preferences>Windows management>Reset saved default positions to default values"
If they aren't there, don't panic
With "Windows>Dockable dialog" you can recreate any of these windows, the difficulty for beginners being to arrange them in "docks" (ie, make them share a desktop window). It's not that hard once you grasp that like in Firefox or Chrome, you have to drag the tabs inside the windows and not the title bars. Drop areas include the side of another window (lits up in blue when you are over it), the "drop anything here" area under the tool box, or the row of tabs (your dialog is then added as a tab).To reset the windows to installation settings: "Edit>Preferences>Windows management>Reset saved default positions to default values"