A few scattered clouds will not be a problem, but hazy conditions or a thin overcast can obscure the light reflected from a satellite. If there are only a few bright stars, conditions are not favorable. Seeing lots of faint stars mixed in with the brighter ones indicates a dark, transparent sky. The magnitude scale used by astronomers ranks the brightness of stars from 1 to 6. The dimmest stars that can be seen without a telescope are mag 6.
Artificial satellites can also be very bright depending on how much sunlight they reflect.
A clear, open view of the sky is important and so is a location that is free from the glare of streetlights. The light from a bright moon can also be troubling. Altitude describes how high up the object will appear. Your hand can serve as a guide for estimating angles. Close one eye, stretch your arm straight out and your fist will span about 10 degrees.