first multi family, looking for advice

[Koen Ballantine]

Hello BP first of all thank you to this awesome community for its knowledge and support over the last two years! i am a 20 year old investor who is in the process of a seller financed deal. the numbers are looking extremely well cash flow is about 1,000 a month, its a three unit with all utilities not included. Next to a private school and the roof and foundation are new or in great condition. Furthermore its first two units are great and can be moved into, the top unit needs some modernizing in terms of cosmetics but other then this is fine, i also will ensure to have it inspected and collect a report along with my due diligence. The problem is this is my first deal and its seller financed, now I will be completely honest, my knowledge in terms of finance dealing with the bank is rough to say the least due to lack of experience, the seller has mentioned a balloon payment and i have never refinanced a house before, what are my risks in terms of a bad refinance and what is any ones advice or some tips you might have in terms of renting and things to be careful of?  I just want to make sure im not going over my head if anyone thinks i left something crucial out let me know thanks for all advice and questions!