Can you tell me on what are the things I need to update in the FAFSA form if ever there are informations that I need to change?
You must update anything that changes your dependency status, for example, you are now pregnant or under legal guardianship, except for a change in your marital status
My friend is also filling out a form and wonders what they should do if their parents were never married ? if that makes a difference.
They would still be your friend's parents regardless of marital status, so your friend should still try to fill out the form with their help.