I already filed my personal income tax for me and my wife but we also have a small business that we need to file. How do we go about that now?

[VolvoGirl]

Yes you need to amend to add Schedule C to your return.  You can keep the original refund.  The Amended return will only be for the difference you owe back.  If you have a Net Profit from your business on Schedule C you will owe Self Employment tax on it.  And by increasing your income you may lose some credits you qualified for.  

How to amend a 2020 return
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-return/01/27439

What version did you use?  You may have to upgrade.  You can enter Self Employment Income into Online Deluxe or Premier but if you have any expenses you will have to upgrade to the Self Employed version. Or any of the Desktop programs. But you will get the most help in the Home & Business version.

How to enter income from Self Employment
https://ttlc.intuit.com/community/self-employed/help/how-do-i-report-income-from-self-employment/00/...

[estherking]

Thanks!! This is helpful and I think I figured everything out now!! I did my tax return o the online version, but bought the Home and Business download for the business already, so I can use that and get everything ready to submit... And the amend my return I filed on the online form!
Thanks again for all your help!