You can use seller financing, or you can use hard or private money.

@Geoff Engel If you don't want to be a landlord but still want to be involved with investing you could be a private money lender for flips or in partnerships and bring the money to the deal.

You probably don't run many applications, so I wouldn't sweat losing a little money on each one.

It's slow money.

By creating a process, you can prevent these issues from taking place and save yourself a lot of time, trouble, and money.

I would rather do this and retain my money then give it to the bank as interest. 

Plus, that is the cheapest that money will ever be for you.  2.65% interest rate? 

Higher risk structures can achieve higher IRRs, but can also break even or even lose money.

If you have a chunk of money to get going I'd personally buy the biggest thing you can if you don't I think house hacking into a 4 plex is great. 

That’s great advice Taz, I’m currently working on saving enough money to get started, house hacking is hard for me at the moment because I just bought a house 2 years ago, I would have to sell my house(which is in a great neighborhood great location) and use that money to fund the duplex which isn’t totally out of the question, I would like to keep the house if possible but also would like to get real estate investing more.