My control number is 1 on my W2. why does it say invalid?

If you are trying to import your Form W-2, don't all W-2s are eligible for importing.  With a single digit in the control number field, I doubt your W-2 is eligible.  You will need to enter the form manually.

Yes, I actually did enter the information of the W2 manually.

Leave the control number blank in TurboTax, it is not needed to file your tax returns with the IRS or State governing bodies, rather it is used by your employer for their internal purposes