Problem using F12 to get specific info on the screen
In Chrome, right-click anywhere on the page and select Inspect element. This will bring up that window on both Mac or Windows.

Alternatively,

For Windows:
Click on the menu (the little button on the top-right, with 3 orange horizontal lines in your screenshot). Click on Tools > Developer tools.
or
Click Ctrl+Shift+I

For Mac:
Click on View > Developer > Developer tools
or
Click command+option/alt+I


If you want the F keys to work more like Windows, follow these steps:

NOTE: After following these steps, I was still unable to bring up the Developer Tools using F12 on my Macbook.


Go to System Preferences. Click Keyboard. On the Keyboard tab, check Use all F1, F2, etc. keys as standard function keys. You will now have to press the fn key to make the F keys do what they show in their pictures. For example, you will have to press fn+F11 and fn+F12 to turn up and down your speaker volume (or at least thats where the volume controls are on my Macbook).





In the same window, click on the Shortcuts tab. Uncheck any shortcuts that use F keys.




Your function keys should now behave more like Windows function keys, though not always exactly the same.