In the case that you need help to reset to defaults you can use the following steps from this AKN article. 

To reset the palettes:

• Click the Window menu and choose Reset Palettes or enter RESETPALETTES on the command line.

To reset the entire program:

• Hold down the Shift key while starting AutoCAD for Mac.
• In AutoCAD for Mac 2015 and newer, you may click the AutoCAD (or AutoCAD LT) menu and choose the option to reset the program.

• For all versions of AutoCAD for Mac, do the following:

1. Click Preferences under the AutoCAD menu.
2. Click the Application tab.
3. Click the button "Reset Application Options."
4. Click "Reset AutoCAD."

Sarah Emmsley
Technical Support Specialist