The keyboard arrow keys navigate/focus on menu bar

Bloodmoney,

Thanks for providing us with the screenshot and your macOS version. You can follow these steps to use your keyboard like a mouse with Mac:

1. "On your Mac, choose Apple menu  > System Settings, then click Keyboard  in the sidebar (you may need to scroll down).
2. Turn on “Keyboard navigation.”

With this option turned on, you can use the Tab key to navigate to all controls on the screen.

To return to making the Tab key only navigate to text boxes and lists, turn off Keyboard Navigation."

Also, check out this resource for assistance with keyboard shortcut: Use macOS keyboard shortcuts

Let us know if this helps.

Stay safe and well.

Hello bloodmoney,

This behavior with the arrow keys focusing on menus could be expected dependent upon your settings.

You can use your keyboard like a mouse to navigate and interact with items onscreen. 

1. Choose Apple menu  > System Preferences, then click Keyboard.

2. Click Shortcuts.

3. From the bottom of the preferences window, select the checkbox “Use keyboard navigation to move focus between controls.” (In macOS Mojave or earlier, this setting appears as an “All controls” button.)

Learn more here: Mac accessibility shortcuts - Apple Support

Also, how keyboard shortcuts work in Finder is a bit different:

- Right Arrow: Open the selected folder. This works only when in list view.

- Left Arrow: Close the selected folder. This works only when in list view.

Have a look at the 'Finder and system shortcuts' section here for more information: Mac keyboard shortcuts - Apple Support

Take care.