Do all 3d block elements form amphoteric oxide in any oxidation state? If not could you clarify which of those?

We cannot predict acid, base, amphoteric properties of any oxide, based on d shells. CO, CO2 [& C2O3] are oxides of C - they are neutral, & acidic !Several factors decide the behaviour of oxides

What we do is : prepare the oxide, test its properties, record them for future generation !

If you really mean just the 3d elements, then it's Cr and Zn.