It's unclear if I need to mail in my return or if it went through I tried using credit karma, but it didn't work

If your return was filed then you should have received an email from TurboTax letting you know that it was submitted and accepted.  You may have to check your junk email folder for them.  In addition, if your return needs to be mailed in there should be mailing instructions on the first page of the downloaded copy of your tax return.

@crossmaddie2