My first home/investment property? How much should I spend?

[Tyler Immeker]

I am very new to this so please forgive my ignorance. 

I would like to buy a duplex with an FHA and rent out the other rooms. This would be my first home purchase and first time getting into investing.

I live in DFW so everything here is sky high right now. I think I could still make it work but I need some advice. Is there a formula for how much you should spend on the house vs how much you should be able to reasonably charge for rent? I don't want to buy the house for "X" amount and then not be able to charge enough to break even or, best case, have some passive income. 

I'll continue to listen to the podcast and read the forums but if anyone has any advice or suggestions, I would greatly appreciate it!