I used Geometry Nodes in Blender 2.93 and was about to use it again together with old projects in Blender 3.0.1 but a lot nodes do not exist anymore and I can not find where to look up what to use instead. Fore example before I used Attribute Fill node, for make a new attribute 'scale' now, but there is no Attribute Fill node anymore. Same for Vector Distance, Point Distribution, Attribute Color Ramp, etc.. Is there somewhere an overview what to use instead the old nodes? I am completly lost now. Thanks!
You can find an overview of the changes in the Geometry Nodes 3.0 Release Notes. The major upshot is that Fields were introduced and attributes were deprecated. So basically you have to find a way to do with fields what you had previously done with attributes. Geometry Nodes Fields: Explained! is a good introduction to the differences that contains an example of converting a 2.93 Geometry Nodes node tree to a 3.0 format.