Do you know something about your area that indicates it will improve?  

I've spent $5,000 on repairs/replacements/improvements.

I'm focusing on learning as much as I can, while I save up and improve my credit.

With that being said, don't immediately make changes if you don't see results immediately... however if the ROI is consistently low, then you should be figuring out a way to improve the marketing.  

I bought my first property cash ($45K) and put ($15K) into it for improvements (new kitchen, appliances, paint, turning the attic into a 3rd bedroom among other things).

You want to be really careful to not over improve, but if you can get them looking a little nicer than the surrounding properties, you can attract better tenants.  

Many in my generation are fearful of home buying until they are making big bucks because they lack knowledge and confidence with regard to basic home maintenance!

As the area continues to turn around I plan on gradually making larger improvements, most notably washers/dryers in each unit and roof decks the units.

. - More and more of the "bad" areas are getting rehabbed, so over time, they could see some improvements.

Seemed strange to me but, I gave him my complete confidence.