Stop waiting until you know enough to start
There is no point where you'll suddenly feel ready. I've watched people delay starting for months waiting to feel confident enough, and the people who actually get good are the ones who started while they still felt unsure and learned the rest along the way.
Waiting to feel ready isn't caution, it's a way of avoiding the discomfort of being bad at something new for a while. Everyone who's good at building things now went through that same uncomfortable beginner stretch. There's no shortcut around it, only through it.
Try this today: pick the smallest possible version of the project you've been putting off, and start it today, even if you feel completely unprepared. Give yourself permission to be slow and clumsy at first. That discomfort is not a sign you're doing it wrong — it's a sign you're actually learning.