Sort your business files so anyone can find anything

Help me sort my business files.

What I have: [invoices, receipts, photos, contracts, staff files, marketing]
Where it lives now: [phone, email, laptop, cloud, USB]
Who needs access: [staff, accountant, partner]
What must stay private: [e.g. staff records]

First ask me up to 4 short questions. Wait for my answers.

Then:
1. A folder structure no more than 3 levels deep.
2. A file-naming rule with examples.
3. Who gets access to what.
4. An afternoon plan to sort it, in hour-long chunks.
5. A back-up check, with the NCSC page on backing up data.

Only use what I've told you, leave blanks for anything I haven't given, and don't invent facts or figures. UK English.

For the NCSC small business guide on backing up data, use web search and name the page you used. If it doesn't search on its own, open View all tools and choose Search.

Stay in this ChatGPT chat. Do not turn on apps or connectors, and do not use memory from another chat.