It's your money. 

Phenomenal CoC returns, recycle your money, ability to scale, etc. 

Pick deals based on how much money they'll bring in, where they are, and how many people want to rent there.

Depending on other factors (credit score, property location, etc) you can look into the hard money route.

Some of the guru's talk and talk about no money down, yadda yadda, but that's just not the norm from what I've seen. 

Theres two concerns here, time and money. 

I have seen money pass and wasted that could have been growing right now.

You are paying money thinking it will bring you business, when in reality it's just bringing you a bunch of contacts that aren't serious.Build relationships.

Businesses that only charge, say, 8-10% on rent and that don't charge ancillary or per-occasion fees are not making any money on the landlord's property, unless of course they are not hiring any staff to provide full service, in which case, I would stay clear. 

Since I am 19 I don't have tons of money to just go and buy a property to invest into.