Worked in multiple states WI,GA,MI and CA is home. While taking tax credit for CA TT is asking me for Adjusted Gross Income (AGI) Taxed by Wisconsin. Can someone help me?

So it seems you are filing nonresident returns for WI, GA & MI. Prepare those first in TT all the way to completion.

Then prepare your resident TT/CA return. TT/CA will "reach" into those completed nonresident returns to gather the information it needs to prepare the Other state tax credit for you. It needs the income taxed by those states that is also taxed by Calif, and the tax attributable to that income.

Thank you for that, now when I tried started my WI returns, it is asking me "School Code and Tax District Information" Asking me if which county I lived in Wisconsin on Dec 31 2018. Is TT broken or something. This is so frustrating. I only stayed in Hotels in WI and that too til April. I cant skip this step, cant go back too. Stuck!!!!

Seems like that's a resident of WI question it's asking. Are you sure TT/WI knows you want a nonresident return?