I got my first non-minimum-wage job ($12.50/hr part time) while living at home at age 19 in 2011. Saved around 90%.
Bought a (very) small house with my girlfriend (we were 20 and 19 at the time) at the bottom of the market in 2012 for $18,500. Put $3,500 down on 5-year owner financing at 5%. Monthly payment PITI was just over $400. Two roommates moved in with us (her sister and sister's boyfriend) to split costs and live dirt cheap. We put about a grand into some new paint, floors, and other small basic stuff. Lived there about a year.
Rented it out after that for about enough to break even with zero cashflow when all costs considered (vacancy, repairs, etc). Still at this point now.
After a shitty tenant left last year, my girlfriend's sister and sister's boyfriend moved back in by themselves this time. And they're awesome.
I still owe about $3,000 on it, and it'll be paid-off next March. Market value is probably about $25,000 now conservatively. Might sell when current tenants leave.
My girlfriend and I bought another house last May. This one is more of a "real" house, bought with a real 30-year bank loan too. It's a "cosmetic fixer-upper" meaning everything works, but plenty of the house is "outdated," last updated in the early 80s. We bought it about $10k undervalued, and are putting enough work into it slowly to probably sell in spring 2018 for about a $20K all-in profit. Or, depending on situations and goals, it could be rented out for positive cashflow.
So the first house was the cheap-living-turned-cashflow-neutral-asset-builder brand of house-hacking, and the second is more of a live-in slow flip.
I did get pretty lucky with the first house. I did plenty wrong. I now know that I almost assuredly could have gotten the house for less. The way we split costs while living there was dumb. I had a bit too much vacancy after we moved out. I screened tenants badly. I was too lax about collecting rent (until I wasn't). Luckily, I bought it right enough that even with all my screwups, I can't help but make money on it.
I know a few people that got burned attempting such things. A guy I work with bought a house for $240,000 in early 2008 with the plan to flip it over the next year. Yeah... that didn't happen. He lived in it until selling it last year as a short sale for $140,000.
Shit happens. Have an exit plan. Have a Plan B. Have a Plan C. Pad all your numbers conservatively because everything will cost more, take longer, and make you less income than you think.