What are all of the expenses of owning an apartment building

[Chris O'brien]

For example, lets say I buy an 8 unit apartment building 100% cash. The property brings in $800/month/unit. Potentially $6400 a month and $76,800 a year. I'm looking for a very rough breakdown of the costs to keep the building operating. Lets say the building is valued at $350,000 here in Western Massachusetts. Not looking for exact numbers, just rough estimates so I can become more familiar with the expenses. Thank you