The 4th level spell Watery Sphere creates an area of water as the name suggests:
You conjure up a sphere of water with a 5-foot radius at a point you can see within range.
To my understanding, a 5ft radius centered on point takes up 4 squares on a grid.
The cantrip Shape Water allows you to manipulate an area of water:
You choose an area of water that you can see within range and that fits within a 5-foot cube. You manipulate it in one of the following ways:
The effects include freezing the water, animating it, changing its flow and changing its color.
The spell affects water that can fit in a 5ft cube, which Watery Sphere is larger than. Shape Water specifies that if there are creatures in the water being effected, you cannot freeze them in it. But if for whatever reason you wanted to cast Shape Water on part of a Watery Sphere, would you be able to?
To clarify, I am not only asking if you can partially affect the spell despite it not fitting perfectly into a 5ft cube, but also if the Watery Sphere's water can be targeted by Shape Water at all, I think the answer to that would be yes because the spells description states the Watery Sphere is comprised of water, and thus would possess all the properties of water?