What are the objects that are visible from a city? I live in a light polluted city of the northern hemisphere and I would like to know what I can see with my Skywatcher BK 707AZ2. I have already seen Jupiter (and its moons), Saturn, Mars, M45, the Double cluster, M42 and, obviously, the Moon.

M31, M13 and maybe M33 are also probably visible, but what else?
We can't know this without knowing what the sky is like for your city. However, you can determine what the limiting magnitude is for your location, then you can set planetarium software to only display catalogued stars that are brighter than this limit. You can do this for naked eye objects, but you could also do this using your telescope to find the limiting magnitude for your equipment also.