Snow ball my first house or not?

[John Henry]

so I just bought my first rental in April which I rent out 3 rooms for 440 a month a piece so just over 1300 extra cash and also live here as well. My mortgage is 675 and my utilities are right around 200. I have a full time job and have no other debt. I guess my question is would it be smart to put all my extra income and a good portion of my own income into the mortgage and just pay it off in 3 years or should I look at other investments. My parents have 23 houses but they never did the snow ball effect but I'm kinda leaning towards it to start out and would really love some extra insight on this subject. I do also have a bit more repairs and is another reason I don't want more properties cause I'm still fixing this one and I'm doing all work myself to keep the expense low