Please Explain

[Luke Woods]

let's say I invest in a rental unit (duplex) and after I subtract my income from my expenses (mortgage, insurance, management fees, vacancy, maintenance, property taxes) once I take my gross revenue and subtract it from my expenses and it comes out that I would make about $200 month off the property. Is this good or bad? Because it didn't pass the 2%rule and I don't think it passed the 50% rule(I am not too sure on how to calculate the 50% rule though)

My goal in this investment is to have it essentially pay for itself to where I don't have to worry about it, or have to put my own money into repairs. Note I would have a 5k-10k emergency fund just for this property upon purchase. I hope this all made sense lol and I could get some answers