I do not want to be “tracked/traced” by way of my iPhone; how can I prevent this, please?

The COVID-19 contact tracing API in iOS 13 does NOT track you by default. It is there so that developers can build contact tracing applications. In order to be tracked using that, you would have to download a tracking app and manually enable the API. It is disabled by default.

Don’t use a cellphone or any device that connects to a network.