Being 17, I know i cant start house hacking till I'm a little bit older and have some money for a 3.5% Down payment on an FHA loan. I am planning on living with my parents for a year after college while working a full time job in Finance. I have some questions and it may be early but i want to learn as much as I can!

How do you spot a deal that is too good to be true? I went into Trulia, the real estate app, and found some multifamily houses for sale. I crunched some numbers, added up the rents for the 3 units of the 4plex, and once i subtracted the estimated mortgage, the Cash flow was about $1,300!! I feel like I might be missing something, because when i listen to Biggerpockets and the stories that people share about their house hacks, they are super excited and say they are lucky if they can make $500 in cash flow every month. I've done this with a couple other properties and noticed that it was around the same thing. I added up the numbers and after 3 years of househacking + buying with conventional loans, I could be making $8,000 a month in passive income in 3 years! Again, this just sounds too good to be true, and I want to learn as much as I can before I am ready. I know that mistakes are a great way to learn, but minimizing simple calculations would be great. (In mortgage calculations I also took out HOA, Utilities, A month of not having a tenant, and $500 for repair safety).

Also, is it easy to find tenants for a property? I've heard that property managers are a great thing to have, but if I can hold off on one for a while then that would be great too, just so i can maximize my cash flow to get the snowball rolling.

I am not asking for a mentor, just some advice. So if anyone has any that has been in the game, I would greatly appreciate it! Thank you!