I can’t find a way to adjust the vertices unless I do it at the very beginning.
This is actually just how operations work with Blender. If you’re coming from Maya you may be expecting a mesh history feature where you can go back to adjust any single operation at any point in time. Blender only offers this kind of adjustment at the time of performing the operation. Scaling and rotating are separate operations that terminate the ability to adjust the creation operation.
It can take some getting used to, again if you’re coming from Maya or another program that works this way. On the other hand Blender has modifiers for non-destructive modifications which Maya doesn’t have.
