High albedo vs low albedo
tl,dr: low albedo = warming (more energy absorbed); high albedo = cooling (more energy reflected).

In principle, and grossly simplifying, energy from the sun warms the ground and less the air. The overlying air is then warmed by the ground, leading to convection, pressure differences, and all that.

So, a high albedo atmosphere would prevent sunlight from reaching the ground, having a cooling effect. Equally, a high albedo ground would reflect more sunlight, less warming the air. That's why glaciers or pole caps of ice have a feedback effect on cooling.

Furthermore, wavelengths reflected by clouds can help cooling an area by day, but also trap warmth radiating from the ground when they move over it. That depends on the situation.

A low albedo atmosphere would let more sunlight pass. In conjunction with a low albedo ground it has a warming effect. Again a potential feedback when ice starts to melt and exposes more ground, leading to more warming, etc.

An open sky will allow warming of the ground by day, but also partly cools back to space by night (continental or desert climate). Greenhouse gases are those that reflect this emitted radiation back instead of letting it escape into space.

Highly populated areas can have a "heat island effect", because of the low albedo of asphalt and concrete and the lack of plants and foliage to absorb sunlight for photosynthesis and evaporate ground water and thus cool.

That (highly controversial and IMO only driven by economic interest) geoengineering thing is about raising the albedo of the stratosphere in order to reflect more sunlight before it reaches the ground. Its adverse effects on ocean acidification and damage to marine life and terrestrial plants and animals ("acid rain") and unresolved side effects could outweigh the potential benefits. But that is a discussion on its own, IMO.

Hope that helps.