Making living at doing photography is a business, with the photography taking up maybe 25% of the time and the rest of it being marketing, selling, administration, book-keeping, contact management, risk management, client management, and if you get there, employee management.
In any business, specialization matters, because the time it takes to do stuff decreases as specialization and experience increase. Less time, means less cost, means perhaps making more than slave wages because your gross margin is up. Specialization also means fewer competitors, and a better chance that your specialty will be seen as unique and therefore worth paying money for.
There are a number of business models.
One: Low margin, high volume, strictly commodity-level stuff. Caters to the price-sensitive (another word for cheap) buyer. CostCo, Walmart, big-box style. Photographic style – santa pictures or on-line catalogue. Few competitors as few can make any kind of money on this unless they have it down to an efficient process.
Two: the opposite of the first – very exclusive, very high price, very unique. Exclusive domain of the “name” photographer. Huge talent, even bigger ability to self-promote, and even bigger amount of luck. Few competitors, as the other “names” don’t shoot in the same style.
Three: something in between. A very hard place as clients want to get the higher-end quality, but pay the lower-end price. Lots of competitors. Specialization and efficiency key to making it a business instead of a non-profit hobby.
As for the OP’s idea that you don’t need college – um, literacy, ability to synthesize, ability to seek out relevant information, knowing the context and the background to a story or a technology… those are all the things that college and university training give you. If you’re in business for yourself, you better know how to write well enough to market, clearly and precisely enough to write a contract, know enough math to figure out a projected cash-flow, know enough psychology to understand what motivates people to buy, etc. etc. Do you know how to research something “from scratch”? If not, remember that technology changes every few years – how are you going to keep yourself current?
It’s easy to start being a business person. It is damn difficult to do it successfully.
Learn a trade or a profession. Then do photography for the love of it, as a way to relax.