Buying my FIRST Rental need advice!

[Mario Nunez]

As stated, its my first rental... super nervous and excited.The property sits on a corner lot roughly on block from the local community college. Some houses are selling for 120 others are going up to 230 in that area. This property has a 2 different units. Unit A is 3/2/2 rented already for 1100/month, unit B is 1/1 rented for 700/month. 

Here are some numbers, I am offering 150k possibly less for the property. Lets say 150k, my mortgage/taxes and insurance would be 1158 roughly, total income on property is 1800 so basic math leads me to believe its a $600 monthly profit right? 

Yes, the house needs some TLC. its outdated and could use some work (15-20k) however the back unit also has a 20x40 garage behind it which I'm considering making into a 2 bedroom attachment and making the 1/1 into a 3/1 possibly a 3/2. Now I'm talking about way more money for this, but would it be worth it in order for me to rent it out to some local college students and bring the price up to about 1000/month? 

Again, this is my first rental property. I don't want to make a decision that will set me back in this industry but I also don't want to be waiting around for another property to come on the market. Also, this one has been on market for about 2 months as of now.