Starting out: Buy One a year or Pay One off?

[Brice Poole]

I am 21 and would like to start building wealth with passive income. My cousin and I are going to partner to start building a real estate empire. I personally would like to continue buying properties to rent out every year but he feels that is risky and will lead to unpayable debt. He would rather pay a property off first before buying another. Can I receive some opinions on the options and what I should tell him to convince to build wealth faster.