Using other people's money...?

[Tim Pommett]

I've just graduated from college, and don't start my new engineering job for another week. In the mean time, I've been reading a bunch of books and attending seminars on how to manage my finances. One of the first authors I turned to was Dave Ramsey, who's extremely opposed to debt. At the same time, my ultimate goal is to achieve financial freedom by the time I'm 40, and real estate is the way I've chosen to get there. Many people on bigger pockets are advocates of using "other people's money", which is basically debt (right?) and conflicts with what I've read from Dave Ramsey's material.

My question is: How risky is it to use other people's money? I posted this in the Starting Out section because, well, I'm just starting out with EVERYTHING... Handling my money, real estate investing, etc. Because of this lack of experience, I realize that it could be easy for me to make a mistake. I have an open mind, I just need some help reconciling these two philosophies.