I am flexible and willing to do what is fair and common practice.

Cody has some really good tips, however the strategies he mentioned are fairly common and might not work as well in our market.

Once I've gotten a fair amount and I have some income coming in every month I wanted to go bigger and invest that into apartments.

But since you asked, I do have some fairly strong ones.

Keep in mind that many companies have salespersons to do their estimates (and @Nicole W. and @Russell Naylor) and may not ever step foot on the roof (if only for insurance reasons).Unless there is something pretty unique, estimating roof work is fairly simple.  

I too am fairly new to real estate investing and am super excited about the opportunities.

I have a few properties in that area so I am fairly familiar.  

You likely will want to be fairly close to at least one grocery store, and some what close to other amenities like restaurants, coffee shops etc.

Also something to remember is if you do not have a policy written down and you "Pick and Choose" in the eye of the tenant you could be sued for a Fair Housing / Discrimination Lawsuit.. always put it in writing and treat every prospect identical...

Most investors budget 8% for vacancy and 8% for maintenance which I think is fairly accurate to cover maintenance and rent ready cost associated with vacancy.