Starting a business that's actually profitable is a pipe dream for most guys. Most small businesses fail within the first few years and a good chunk fail within one year. Out of those that fail within the first few years (which again, is the majority) most never generated a profit. I dont even think I've ever known anyone who started a business that was profitable and lasted even 5 years.
Maybe it was a semi-realistic dream some decades ago, but these days so much more wealth is consolidated behind a small number of megacorps...and since they can buy in much larger quantities you can (thus will have a lower cost per unit) they will undercut you all day. And of course they'll have an infinitely higher advertising budget and brand recognition. Sure, you can get into a niche market, but if the demand for any good or service you can provide is high enough to generate a profit enough to even sustain a modest lifestyle, it's guaranteed you'll have competition, and they'll have a huge head start on you. And whatever idea you think you have, it's nowhere near as original as you think it is.
Basically if you don't have a high IQ or a marketable talent, any business you start will just be a money pit. And even if you possess one of both of those traits, it's far from a guarantee.
Oh, and if you're thinking "I'll just buy in bulk from alibaba and sell on amazon/ebay" everyone and their cousins has come up with this idea. Those who try usually end up with a garage or storage unit full of shit they end up tossing or selling at a huge loss. Give up before you try.
