Advice For Starting Investment Propert Owner

I am an 18 year old in college, deeper aren't in need of advice to kick start my dream! One day, I want to own multiple investment properties that I rent out/ sell/ buy for profit. 

I don't have the slightest idea on how to start this though. What do I do?

I'm from Phoenix, Arizona if that helps! 

I need to know where I should invest. How much I need to save up. What investment should I make. How do I make it.

Or even just tips on what to do, what to look out for, ect.

Thank you!