What measurement is for.
WHAT IT TELLS YOU
Whether anyone visits Where they come from What they do Whether they contact you or buy
WHAT IT DOES NOT TELL YOU
Why they did any of it.
Numbers show what happened. They do not explain it.
WHY IT MATTERS
Without measurement, you are guessing about what works.
Money spent on promotion with no measurement is money you cannot evaluate.
THE MOST USEFUL THING TO MEASURE
Enquiries and sales.
Not visitors.
WHY
A thousand visitors who do nothing are worth less than fifty who contact you.
WHAT MOST BUSINESSES MEASURE
Traffic, because it is the easiest number.
WHAT THEY SHOULD MEASURE
Whether the site produces business.
WHERE TO START
Set up analytics, set up Search Console, and record when someone contacts you.
Those three cover most of what you need.