1. Right Click
Click the right corner of your Apple mouse, or click with two fingers on your Apple trackpad. You can change this in Mouse preferences and Trackpad preferences. Settings for scroll direction, swipe gestures, and button assignments are also here.
2. Close & resize windows
Buttons for closing, minimizing, and maximizing a window are in the upper-left corner of the window.
3. Change volume
Use the controls in the menu bar, or use the volume keys on your the keyboard.
4. Find files
Use Spotlight to quickly find and open apps, documents, and other files. You may also check Finder if you are looking for a File Explorer to browse files?
5. Open apps
You can also use Launchpad and the Dock to open your apps (programs).