Find out where your customers actually come from

Help me find out where my customers really come from.

My business: [what you do]
Where I market and roughly what each costs per month: [e.g. Facebook ads, leaflets, Google profile, local magazine]
How customers contact me: [e.g. phone, website form, walk in, WhatsApp]
Who takes the enquiries: [me, staff]
What I'd count as a result: [e.g. enquiry, booking, sale]

Ask me up to 3 short questions first. Wait for my answers.

Then:
1. A simple tracking sheet: date, name, how they found me, enquiry or sale, value.
2. The natural way to ask "how did you hear about us?" on the phone, by email and on a form.
3. Simple ways to tell channels apart, such as a code word on leaflets or separate links.
4. A monthly check: what to add up and how to work out cost per customer for each channel.
5. What to do after 3 months: keep, change or cut.

Simple enough to keep up, UK English.

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