Hello from Virginia! (+ 1st question)

[Peter Pascoe]

Hello! I have found quite a gem here- this website it great! I am active duty military in the beginning stages of researching for my first piece of property. I do not know where to go with my first question so here it is.

I am 26, and currently renting a home for $1,550 month. The house is worth $230,000. A friend of mine owns it. He has recently retired from the military and offered to sell the home to me. I said no, because I would like my first house to be closer to $100,000. Here's the kicker- the house has a apartment above the garage with a private entrance. Which I have been renting out for $900 per month. 

QUESTION: If I buy the house and relocate, can I rent out the home and the apartment above the garage separately? Because if so,  taking on a larger mortgage would not be a huge issue. I would be generating more then my mortgage, allowing me to pay the house off faster.

Thanks in advance for any input. I will move my post to the correct forum in need be. Cheers!