Customise the menu icons
The menu bar icons and the information they display is easy to customise through the app’s settings. Click any icon and then the gear in the top-right corner to open Preferences. Select each of the sections and there are often multiple icons to choose from, each showing different information. The type and number of display options varies with the icon selected, so try them all and customise them. Here are a couple of examples and there are many more.
Activity Monitor is good for monitoring what is happening under the surface of the Mac user interface. With an iMac, its window can be placed in the corner of the screen to keep an eye on CPU and RAM usage, disk and network activity. MacBooks don’t have enough screen space and the window gets in the way, but there is a solution.