Just wait until the IRS gets done processing the first return you filed with just his W2 and you get the first refund (or you pay the tax due). Nothing you did after filing his will affect the process or delay it.
So now you need to delete and take out anything you added or changed after filing to put your return back to the way it was when you originally filed it. Then you can fill out an Amended 1040X tax return to add the rest of the info. But you have to wait, the amended return won’t be ready until later in February . Keep checking back for amend instructions.
How to Amend this year
https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-federal-tax-return-curr...
