Don't do it. At least not yet.
Instead, go join someone else's early stage company as employee #3-50 (or so). The experience you'll get over the next few years will be invaluable, and you'll be in a far better position for success when you decide to leave and start your own company. You'll see many processes (e.g. fundraising, product management, leadership, etc.), you'll learn from mistakes (yours AND other's), and you'll build a great network of contacts.
There's just nothing like learning on the job, in context, from those with more experience than you. There's a reason why the apprenticeship system has been the dominant method, for over a half-millennium, to pass the experience of a trade or craft to the next generation.
I sometimes encounter startup teams that are thrashing on basic things, and it's almost always because they're lacking experience. Skill is a combination of (a) knowing what to do, and (b) knowing when/where/how to do it. The Internet is a seductive source of "what", but isn't a substitute for judgement. Reading someone's blog post on their Agile development principles is helpful, to a point. But remember: these anecdotes are necessarily simplified and abstracted, and are missing important bits of context. Someone else's experience may not translate to your situation.
I am not an astronomer, but I long ago remember reading the fastest way to grind a good 12-inch telescope mirror was to first grind a 6-inch mirror. Few builders are successful grinding the larger mirror as their first project, and that's sound advice for startup entrepreneurs as well.
What do you think? Is better for would-be entrepreneurs to just "jump in" or is there value to spending some time learning the ropes at another startup first?