If the effective date of the S-corp is 1/1/24, then you report all the S-corp's income and expenses, regardless of tax paperwork. You do NOT also file a schedule C as a sole prop. The fact that some 1099s are issued in your personal SSN or prior EIN is not what controls how you file. If you made the election as an S-corp, that's how you must file. Getting the 1099s under a prior EIN may cause the IRS to send some automated notices related to your personal return, but you would reply with your explanation that all the income was properly reported under the S-corp.
