No growth hack, brilliant marketing idea, or sales team can save you long term if you don't have a sufficiently good product.
AirBnB happened because Brian Chesky couldn't pay his rent, but did have some space.
If you're not in college and you don't know a cofounder, the next best thing I think is to go work at an interesting company.
In addition to relentlessly resourceful, you want a tough and a calm cofounder.
You really want to know your cofounders for a while, ideally years.
You cannot create a market that doesn't want to exist.