As for how to do it? I'd recommend starting a SaaS business. Pick something - something where you can generate leads reasonably easily, so you don't end up learning marketing, and where you aren't going to need to spend loads of money, so you don't end up learning finance - and set a launch date 50 days from now. Then start designing.
Your project probably won't be tremendously successful - although you might make some passive income, and there's always the chance of an accidental massive success - but you'll learn a hell of a lot, you'll have real-world problems to solve and real-world users to pacify, and IMO "I've built a business on these technologies" plays better on a CV than "I've made some webapps for my own use".