A telescope will show a very tiny half illuminated disk. Uranus and Neptune require a finder scope to even spot as faint starlike points. In the telescope these become noticeably larger than stars. Uranus has a blue hue, while Neptune is decidedly greenish. Spotting Pluto, however is out of the question unless your telescope has a diameter of 12 inches of wider.
Planets are the objects that can benefit from using high power.
However telescopes do have a maximum usable magnifying power. It is 60 times the diameter of the objective in inches. So a 60 mm objective, that's 2.4 inches, can supposedly show added detail up to about 144 power. Any more power gives a fuzzier, dimmer image, despite what the telescope manufacturer might tell you. It's a law of nature, like the impossibility of exceeding the speed of light.