Hi Sixgunner and welcome to SRP.
I can only speak from my (limited) experience and would suggest that, whilst you could get away with one razor, unless you hone it yourself it will need to be sent out to be honed regularly, particularly in the early stages of your journey.
As for having two razors the same, I would consider having two different sizes with the same grind to experience the difference between them FWIW
The other issue that you may not be aware of is the onset of RAD which can increase your razor holdings considerably.
I have five in my rotation ATM with more coming with sizes ranging from 4/8 to 11/16 full hollow to 1/2 hollow.
Other members here have many many more with widely different grinds and sizes and they love them all.
It is up to you how you go through this journey into the world of str8's, however, if you stay on this site you will be exposed to more information/opinions than you ever thought possible on the subject.
Read lots and look through the WIKI, form your own opinions, try as many different sizes and grinds as you can (if possible) and, most of all, enjoy the ride.