Reporting of Investments - After filing of Taxes

First year I've filed taxes in 40 years (my wife always did the taxes before) - so newbie question.

 

I filed my federal and state taxes yesterday using TurboTax Deluxe.  I didn't think I had to file a Schedule D since I hadn't sold off any assets from my 401 and IRA accounts in 2023.   But I guess I need to report them regardless.  How do I file an amended tax return for these accounts using TurboTax?  Is there anything special I need to do or know before doing so?  And is it safe to say that it won't effect my reported taxes since I didn't realize any true income during the year - just capital gains.