Getting started- appreciate advice

[Matt Brooks]

Happy New Year Bigger Pockets! This is my first post and I have been a member for 6 days. I appreciate any advice in advance. My opportunity is:

I currently have a a contract on 5 city lots in a small town in TX. I am purchasing the lots for $20k. $4k down, finance 15 years fixed rate. This is the town I grew up in and is in need of newer/nicer middle class rentals.

Once the city learned of my intentions of possibly building rental units on these lots they would like to speak with me in regards to possibly using city owned lots for construction of even more rental units. 

I will have approx. $50k in cash in June to invest as I see best.

There are apartment complexes in this town but they are old and not well maintained. The town is in need of middle class nice rental units.

Local bank will offer 15% down payment, 7 year loan, 30 year amoritization. 

My initial thoughts are to build a duplex, refinance in 2-3 years, draw equity out and build again. I should have this same $45k cash available annually through my primary career.

How would you proceed? Thank you for your help!!