If I received a letter from the IRS stating changes, how do I make those changes, or get assistance on what I don't understand?

[flukercharlene]

I filed my 2019 taxes but later learned that my IL State E-File was rejected.

[Critter-3]

I GOT A LETTER FROM THE IRS   

https://ttlc.intuit.com/questions/3605673-i-got-a-letter-or-notice-from-the-irs

I AM BEING AUDITED

If you purchased Audit Defense:

https://ttlc.intuit.com/questions/2924451-i-bought-max-or-audit-defense-and-now-i-m-being-audited

AUDIT SUPPORT

If you did NOT purchase Audit Defense:

https://support.turbotax.intuit.com/irs-notice/audit-support/

[xmasbaby0]

You asked about two different issues.  One of them was that you got a notice from the IRS. We cannot see your tax return or your account, and know nothing about what the IRS said to you.  Call one of the support numbers given to you in the earlier reply to your question.

And you also say your state return was rejected.  Since it is now too late to e-file a tax return, you have to print, sign and mail your state return to get it filed.