There are around 2000 satellites that orbits the Earth, of which about 500 are still in use. There are a lot of discarded objects in space that, by definition, are also satellites. There are around 9000 pieces that are larger than 10 cm, and 150,000 that are bigger than 1 cm. These can be very dangerous for an astronaut, a Space Shuttle, a Space Station or a working satellite. That depends on the satellite's purpose.
Satellite orbits are normally either polar or equatorial.
A polar orbit goes, as the name suggests, over the poles. An equatorial orbit goes over the equator. There are also orbits that are tilted so they fly somewhere in between. The orbit could either be circular or elliptical. An elliptical orbit will take the satellite to different altitudes, while a circular orbit will keep the satellite at a specific altitude all the time.