Offer Accepted on First Rental Property!

[Brett Riemensnider]

Just got word yesterday that the seller accepted my offer on a 4plex! Very excited for my first move into real estate. The 4 units are a 3bed 1bath, a 1and 1, and two 2 and 1’s. I will be moving into the 1 and 1 and remodeling while living there. 

Does anyone have any advice for a beginner on just amateur mistakes, things to look out for etc? 
Also what do people recommend for remodeling? Certain materials better than others? Things to avoid or are wastes of money/time to update? Any advice is greatly appreciated! Nervous and excited for this next step in life! Thanks!