What’s the worst part about investing in a multi-family home?
Dealing with tenants
Constant complaints and tenant problems. You get dragged into it if the old guy upstairs plays his tuba at 2 am. Also most people don't want to live in these type houses so you get lots of problem tenants who may play their tuba at 2 am.
Maintenance (if the building isn't new), plus tenants who fail to pay but never fail to have an excuse at the ready. Hire a property management company to deal with it, because it's going to be nothing but trouble if you try to do it all yourself.
That would be the other tenants...or just tenants if you don't actually live there. Maintenance is what it is...
Collecting rents and keeping up with maintenance.
assuming you plan to rent it = dealing with tenants
People fall out.
Mortgage and property taxes i guess?