Macs come with a Dictionary app. It’s very handy. Find it in the Applications folder.
When you launch it, you get this:
EVERY word in the Dictionary is clickable! So try clicking. Also, try the thesaurus and the Apple and Wikipedia sections.
If you hold the Option key while tapping the bright/dim buttons on the keyboard, the Displays preference pane pops up. There’s no quicker way to do it.
One could argue that Undo, Cut, Copy, and Paste are the menu items that make a Mac a Mac. They are always in the Edit menu, and every program uses the same keyboard shortcuts for them:
Guess what? The keys are right next to each other, in the bottom row of the keyboard. That should make remembering them easier.
I don’t know how they came up with the Z for Undo, but that’s OK. I do have some ideas for X, C, and V but only if you ask.