Once you’ve completed your financial aid forms, do you receive a confirmation email?
Also, would the schools notify you if you did something wrong regarding those forms?
There is no confirmation. I think there have been cases on this site in previous years where a school wants to accept someone, but is missing something from the financial aid forms, so they notify them a few days/weeks before March 9th/10th and ask them to get forms in ASAP.
@ThomasBr Thank you 
The school will have access to your online PFS as soon as you have paid for and submitted it. You should receive a confirmation email indicating that your submission was successful, along with a PFS ID Number.
Next you will upload the required documents (tax returns and W-2 forms) by the deadlines set by the schools to which you are applying. You don’t get a confirmation email after uploading documents, but you can see the status of the document on the screen.
Yes, schools will contact you if there are questions or concerns.
These and other questions are answered on the Family Portal at https://sssbynais.force.com/familyportal/
It’s best that the FA portion of the application is handled by the parents.