If I am applying in-person does everyone in the family needs to be present or only one person can submit everything?
Good question. This was pretty hard to Google but I found the answer.
https://www.canada.ca/en/immigration-refugees-citizenship/services/canadian-passports/help-centre/apply.html
Who can submit a passport application in person on my behalf?
When applying in person, it’s best that you submit your application yourself. However, if this is not possible, a third party can submit the application if they:
show identification
are 16 years of age or older
are your
parent
child
parent's spouse or common-law partner
child's spouse or common-law partner
brother or sister
half-brother or half-sister
stepbrother or stepsister
spouse or common-law partner
relatives of your spouse or common-law partner, including their:
parent
child
parent's spouse or common-law partner
child's spouse or common-law partner
brother or sister
half-brother or half-sister
stepbrother or stepsister
In all cases, the passport official must be able to verify the information on the application with the third party. If the third party cannot validate your information, we can refuse your application.
The people in the list above may or may not live at the same address as you. In all cases, the person must show identification. If the identification does not prove that the person lives with you, they must also bring a written statement signed by you, authorizing them to submit your passport application.
Any relative living at your address can also submit an application on your behalf if they:
are 16 years of age or older
show identification that confirms where they live
if their identification doesn’t have an address, they will need to show other documentation to prove they live at the same address as you
We do not accept urgent or express applications submitted by a third party.