Step One: Build something that generates money. Then walk away. You could sell it or you could put into place systems so that the thing you’ve built can continue to exist without your constant attention.
Step Two: Repeat Step One.
When you have enough, stop.
So you ask, “What to build?”
Something niche. Something small is fine. No need to hit a home run. Small successes, repeated over time lead to big wins.
Build something simple. Do something remarkable (so that people remark!) Be remarkable. Then people will come. It takes time. But it will build.
Supply something that not everybody wants, but enough people want.
Again, back to enough.
How much is enough? That part is up to you.