Use VoiceOver to navigate menus on Mac
The menu bar at the top of the screen contains several menus, such as the Apple menu 
, the app menu and the status menus.
If Trackpad Commander is enabled, you can use gestures when navigating menus.
Note: VO represents the VoiceOver modifier.
Navigate to the menu bar
Press VO-M, or double-tap with two fingers near the top edge of the trackpad.
Navigate in the menu bar
Go to a specific menu: Type the first letter of the menu. For example, type “H” to jump to the Help menu.
Go to the status menus: Press VO-M-M.
Move among the menus in an area of the menu bar: Press VO-Right Arrow or VO-Left Arrow. A sound effect indicates when you’re at the end of an area.
Open Spotlight: Press Command-Space bar.
Ask Siri: Press the keyboard shortcut (as specified in the Siri pane of System Preferences). If Siri isn’t shown in the menu bar, choose Apple menu
> System Preferences, click Siri, then select “Show Siri in menu bar”.
If you’re using VoiceOver gestures, drag a finger across the trackpad to navigate the areas and menus in the menu bar. You hear a sound effect when moving over a blank space. You can also flick left or right to move between menus.
Navigate a menu
To open any menu, press VO-Space bar.
To move down or up a menu, press VO-Down Arrow or VO-Up Arrow, or drag a finger down or up on the trackpad.
To move to a submenu, press VO-Right Arrow or flick right on the trackpad. To return to the main menu, press VO-Left Arrow or flick left on the trackpad.
Close a menu
To exit a menu without selecting an item, press Escape, or scrub back and forth with two fingers on the trackpad.
To open a shortcut menu for an item, press VO-Shift-M, or use the customised gesture Control-Trackpad click (you can change this default assignment and assign the command to a different gesture).