If you took the Standard Deduction last year then your state refund is not taxable and you don't have to enter it.
I don't know why you got a 1099G. You have to ask the state. But they are suppose to send you a 1099G if you got a state refund. But a lot of states are not sending it. I guess you are suppose to get it from the state's website. You don't need a 1099G. You should know if you got a state refund last year and the amount.
