1) Legally, you can change your cell phone number at any time you wish. It would be a good idea to send a letter to the court (send to the specific judge on the matter, if one has been assigned, and to the clerk more generally) and to your spouse's attorney (if he/she has one) or spouse (if no lawyer) so you don't miss any important notices or communications.2) If it doesn't apply, write in "N/A" or "not applicable" or, if relevant, a slightly longer explanation. E.g. say a section asks for brokerage accounts: you could write "I do not have any brokerage accounts."