Bring what you have
You do not need a finished file to ask for support.
People often wait because their paperwork feels incomplete. You may be waiting for medical records, have a new appointment scheduled, or still be trying to understand a decision notice. Those are ordinary reasons to begin a conversation, not reasons to put one off.
Bring the notices you have kept, a list of doctors and treatment providers, recent appointment information, and a short account of changes in your health or ability to work. It is also helpful to bring the questions you want answered. Plain language is enough. You do not need to know the right terms before you reach out.