Apple has had Emoji available in the macOS for a really long time. It came over from iOS originally. I use Emoji in the Messages and Email Apps. Occasionally, I even use them in a word processor document. I think most of us are familiar with using Emoji in iOS and iPadOS, but you can also use them on your Mac.
Some Mac Apps have a button for inserting Emoji like the Messages App.
In some Email Apps, Word Processors and other Apps you need to activate the Emoji window. The easiest way to do that is to hold down Control ⌃ + Command ⌘ + Space Bar to produce the Emoji window 😎. Here it is in the Pages App.
Then all you do is scroll or search for an Emoji. You can also activate the Emoji window in the Edit Menu in most Mac Apps.
Of course, you can have the Keyboard Viewer activated in your menubar and just click on it as well.
There are several ways to activate the Emoji window on your Mac. Emoji are fun to use and easy to access.