@Isuf Aruci,
Hi and good luck. i've owned some props on Bx and what Steve Gordon and Ceaser are giving you great advise. Consider your risk tolerance bc you will need it in the bx, although your nhood is slightly better and you should strive for better tenants, Sometimes looking for a better tenant means having the property vacant longer.
confirm that existing tenants have always paid on time by checking sellers bank stmts.
As CR says If you wish to buy more than one consider buying the first on FHA and the second with std financing.
Consider having separate boilers and separate meters for all tenants. Also consider having tenants pay a 90% portion of the space they occupy in water bill if its allowed. (for ex if tenant has 30% of the livable space than have tenant pay 90% of the 30%= 27% of the quarterly water bill) Water rates in the city are rather high now. Have your eviction letters ready to serve and your eviction atty ready also to start the process asap. Bx courts are very tenant friendly. GOOD LUCK