If you're curious, Emacs does all this—and more—with various C-h commands. If you want to see a full list of these, start with

    C-h ?

Here are my favorites:

If you want to see a specific keybinding, like checking what C-w is bound to:

    C-h k C-w

If you want to see the documentation for a function:

    C-h f function-name

If you want to see details about your current mode:

    C-h m

This is incredibly useful because it lists all the mode-specific keybindings. That's how I learn how to use new modes!

If you want to see or interact with a variable:

    C-h v

If you want to see something where you remember just part of the name:

    C-h a *regexp*

(a stands for "apropos")

If you want to see the incredibly detailed manual for Emacs or all of the info manuals on your computer:

    C-h r
    C-h i

If you want to see info about your input mode (how do I type ℕ in TeX-input-mode?):

    C-h I

Actually, for that one, I have another handy trick: copy and paste an ℕ into your buffer, go over it and use

    C-u C-x =

which brings up detailed information about the given character... including how to type it in your current input mode (if applicable). This also includes useful info like its Unicode designation and category.

I've found all of these tricks exceptionally helpful when learning more about Emacs. They also help me overcome my fear of memorization: its so easy to look stuff up, I don't have to bother. Then, if I use something enough, I remember it without especially effort. It's like a cache in my mind.