How do I valuate a small multi-use property?

[James Sloven]

I had just begun my search for my first rental property and my real estate agents just sent me information about a multi-use triplex. It has two residential units and 1 commercial unit.

one of the residential units is currently rented out for $600 a month. It is a 2 bed 1 bath apartment. The other units currently rents out for $550 a month, and it is a 1 bedroom 1 bath apartment on the ground floor. The commercial unit is currently vacant and supposedly rents out for between 300 and 500 dollars a month.this commercial unit has 400 square feet to it.

As I just received this email from my real estate agent, I do not know the current condition of the property particularly that of the commercial unit. Nor do I know the details about the current occupants of the building. 

Right now I am emailing my real estate agent back and indicating interest in the property, butgoing forward I am not sure how to evaluate this property.