Down payment for a duplex

[Jose Zamora]

I’m 19 years old And still currently living with my parents and only paying my personal bills. Also I am a fire fighter as well and I’ve heard I can get some pretty good discounts when it comes to purchasing a home.  I’m interested within the next year in buying my very first duplex. I was wondering how much should I save within the year as a down payment. I’ve heard 20% is usually the right amount. i’m just looking for any advice out there. I want to start house hacking. Just need to be pointed in the right direction.