The first thing one should do if you want to disrupt a market is learn as much as you can about the current state of that market.
This doesn't mean reading it's Wikipedia entry.
Ideally, it means spending several years working for the current market leader in that space.
Barring that, reading as much as you can about the history, economics, mechanics, and current players in that space.
If possible, become a customer of one or two of the market leaders. If that is not feasible, again get to know people who are customers (again they may become your first target customers).
Befriend several people who do work in that space (they could become your first hires).
The deeper your understanding and experience in a market, the more likely you will succeed in disrupting it.