Planetary observations: what to expect from the Powerseeker 50AZ?
Currently, Mars is very far from the Earth, so it appears to be very small. I doubt that any amateur telescope will show any details on Mars in this condition. Perhaps when it comes to opposition and is close to Earth, you might be able to see some faint markings with your scope.

Jupiter should show a sharp disk and nearly pinpoint moons with the 12.5 mm eyepiece (48 power). You should see two prominent bands on Jupiter.

The 4 mm eyepiece is probably poor quality, and since it provides 150 power, is too much power for a 50 mm scope. In ideal conditions, the general rule is 100 power for a 50 mm scope (2 times the scope size in mm). The clarity of the sky is not what makes a sharp image. There is a condition named "seeing" that indicates how sharp the viewing is. On some nights, the seeing is poor, so the images will be soft (not sharp) and perhaps shimmering, as if you are viewing the object through a stream of water. (Essentially, you are, except it is miles or kilometers of air!)