New... Need help with calculators 9 duplex deal

[Benjamin Mercier]

Hi i am new to bigger pockets and real estate investing trying to learn as much as possible. I am currently working on my first flip looking to have it done in August. 

My question is with the calculators i have been using them to run numbers but i want to make sure i am entering in the correct numbers and making sure i am analyzing deals correctly. Here is a 9 duplex (18 unit) 3.4M deal that i ran the numbers on. The numbers show a high negative cash flow. I want to make sure this is correct. 

Also i see some people are using 20% down and some say you need to put 30% down can someone explain to me why they are recommending 30% down. 

https://www.biggerpockets.com/buy_and_hold_results/1123850.pdf?c=1560388484