Updated June 12th, 2019.
One of the best things about the Mac is consistency. That lets you take something you know about one app and use it in another app. There’s no better example than the Mac’s Edit menu, and its stalwart menu items Undo, Cut, Copy, and Paste. The keyboard shortcuts for those are always the same, regardless of the app you’re using:
⌘-Z for Undo
⌘-X for Cut
⌘-C for Copy
⌘-V for Paste.
The keyboard shortcuts are right next to each other in the bottom row of the keyboard, and if you use your left thumb to press the Command key you can type the Z, X, C, or V with your left index finger. This makes those shortcuts easy one-handers, and that’s no accident.
Look for an Edit menu, and Undo, Cut, Copy, and Paste, next time you’re using your Mac. They’ll be there, and so will the shortcuts. Learn the shortcuts once, then use them over and over, regardless of the app you’re in.