If you are passionate about it, pursue it.
I'm twice your age and have a great job(far from detailing), but for some sick reason I enjoy detailing and consider it my hobby. My vehicles are typically spotless, and I get bored working on them because they lack challenges. I've traded my minimal expertise on friend and neighbors vehicles for something as simple as lunch, or just done it because I enjoy doing it and seeing the improvement.
I've been passionate about waxing/cleaning car exteriors since I was a pup helping my dad apply and remove Liquid Glass from his Oldsmobiles by hand. I did EVERYTHING by hand until about 10 years ago, and that still works if you don't mind putting in the elbow grease. If I could just fine some more Blue Max cleaner wax paste, I would own the world(lol). It will take longer by hand, and you will get tired doing it that way, but it can be done.
Focus on learning the products, polish vs. cleaner wax vs. pure wax, sealant, coating, etc if you don't know that already. Then within that learn about the differences in polishes (names get confusing, finishing polish, swirl remover, compound, etc). For all intents and purposes, they are all the same with different cleaning / correcting capabilities.....I'm oversimplifying this. Autogeek has a great guide on their polish page giving you some idea of the differences in cutting / cleaning abilities of polishes.
For now, ignore the comments that you need x polisher with y pad and z polish to fix a specific problem........if you don't know the capabilities of a specific product, the tool won't matter much. Does a power tool make it easier, yes.....does it limit your ability to fix a problem, not necessarily.
I'm guessing your friends and neighbors would be extremely satisfied with a clay bar, hand applied cleaner wax, (more elbow grease where there are minor problems).
Hope this helps!