@Driton Selimaj. Your expecting a lot! With $300k you could purchase something in the $700k-$1m range (lenders will require you to keep some for cash reserves).
How much are rents in that area For that type of unit?
What are the costs for the particular building? Will you be paying w/s/g? Hot water, electricity? depends on the building.
What are your other costs? Yard care, snow removal, management fee, repairs, routine maintenance, insurance, taxes, reserves for major issues (hot water tanks, furnace, roof, etc).
As a rule of thumb, you can figure approximately 35-40% in expenses, and then add your mortgage payment. If you can net $200 or more per door after that your doing alright.
I have a 10 unit that I got a great deal on that nets about $3k/mo ($300/door), -but I’ve also tripled the value in 4 years by cleaning it up and getting rents up to market!
So there’s cash flow along with some significant equity building. Good luck in your endeavors!