The most FA of all the FAQs.
Here’s Laura Kalbag:
Find what you love. Don’t worry about needing to learn every language, technique or tool. Start with what interests you, and carve your own niche. And then use your powers for good!
And my own:
Buy a domain name. Figure out how to put an HTML file up there. Isn’t that a powerful feeling? Now you’ve got table stakes. Build something.
Definitely, go read other A Book Apart author answers because they are all great. My other favorite is just three words.