The Calvin Cycle occurs during photosynthesis and makes a glucose (sugar) molecule. It happens after the light-dependent reactions in photosynthesis.
The Calvin Cycle is called a light-independent reaction because it does not directly use light to function, but the outcomes of the light-dependent reactions that occur before the Calvin Cycle are actually a vital part of the Calvin cycle. In other words, the Calvin Cycle is indirectly dependent on light. To go through the cycle, it uses ATP and NADPH molecules that were produced during the light-dependent reactions. With ATP and NADPH as fuel along with some carbon the Calvin Cycle goes through three steps like Carbon Fixation, Reduction, and Regeneration which will, in the end, make a sugar molecule.
All of this began with an intricate design of creation, some photons (light waves), and water.
Khan Academy on ‘Photosynthesis: Calvin Cycle’ https://www.khanacademy.org/science/biology/photosynthesis-in-plants/the-calvin-cycle-reactions/v/photosynthesis-calvin-cycle