Right now I'm on the verge of starting a Vanguard Total Stock Market Index fund. Would this produce income for me in say 15 years?
Sure. It would also produce income for you tomorrow. Invest $1000, and then tomorrow, sell it all to produce ~$1000 of income. Sure, that $1000/day income will only last for one day, but who cares about that? You just want
tha income, right, no further details necessary?
It's not like after 15 years your Total Stock Market investment will suddenly emerge from its cocoon, transformed from an "investment" into an "income-generator". Every investment can generate income at any time (by selling all or part of the investment), so the key is figuring out what investment you can expect to
sustainably produce your desired amount of income over your specified period.