NICE guidance on dementia says that at diagnosis the person and their family should be offered spoken and written information on several things.
They include which type of dementia it is and what changes to expect, which health and social care teams will be involved and how to contact them, how dementia affects driving (they need to tell the DVLA and their car insurer), legal rights, and local support groups, financial and legal advice, and advocacy services.
NICE also says to ask the person, at diagnosis, who services may share information with, such as family or carers, and what may be shared, and to record the answers.
If none of this has been covered, ask.