When I use the normal baking built into blender, all the places where it should have baked normals, it renders a transparent image instead. I followed a bunch of tutorials, and yes indeed, I did "enabled selected to active", select the high poly object first and then control click the low poly one. Has anyone experienced this prior, or an idea on what might be going wrong here? (Blender 4)
So I think I might have figured out what's going on here.
You have a cube you are baking to when you have the 'enabled selected to active', yes?
Try adjusting the values to match what your geometry is doing between the two cubes if that is the case.
The 'Extrusion' value will grow your selected object by that many units before the bake.
The 'Max Range' value will determine how far past that extruded layer it will look for geometry to render.
If your target cube is pretty close in size to your sculpt, it shouldn't need much changing. But, if parts of the sculpted geometry intersect your target cube, you might generate artifacts in the bake like what you are seeing.
If that still isn't working, try skipping the 'target object' option all-together by changing 'Space' to 'Object' and plugging in a 'Normal Map' Node into the 'Surface' slot of the 'Material Output' Node of the sculpted object's material shader.