Cities and Suburbs change. Even an empty field with one sad cow in the middle is valuable twenty years later when the place is all built up. So you can document for future residents, just shooting as it exists today. Might take on meaning later.
You can also do a 'day in the life', starting at dawn with the garbage trucks, newspapers, etc. Then school getting out for lunch, then commuters coming home, street lights coming on.
Failing that, there's always people. They crack me up. You could wander around, chat, take pictures, show pictures, everyone in the neighbourhood gets to know you. Someone gets a new car, or graduates, or has a sister visiting -- you take the picture.
Art (capital A) sort of happens along the way if you just make photographs, I think.