Converting a Duplex to Single Family?

I am likely purchasing my great-great grandmother’s 1920’s bungalow in Memphis, TN that was converted to a duplex from a single-family around 1930 so she could have income from taking a tenant during the Depression.  Well, my husband and I want it back!  According to my aunt who currently owns the house, there are two sheet rock walls now where french doors were in two areas of the home.  We have NEVER torn down a wall or really done a single thing and though we are very excited, we are intimidated too.  Anyone else out there every taken this on?  We will also have to update the electricity and have CHA installed also.  There is a basement and floor furnaces so there is no need for wall duct work.  Any clue as to what this could cost?

THANKS FOR ANY ADVICE or LEADS!

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