Analytics
The tools that count who visits your site and what they do. Without them you are deciding blind.
The useful minimum is how many people arrive, where they came from, and how many tap the call button. That is enough to make decisions.
It is easy to fall into staring at charts daily without changing anything. For a small business, checking once a month is enough and more useful.
The number almost nobody measures and that matters most is how many times the phone gets tapped. It is the closest you get to counting calls without a tracking number.
What to do about it
Ask whether your site measures taps on the call button. If it does not, you do not know whether it works.
Other words about the same thing