How to connect to free WiFi on iPhone?

Can you tell me the step-by-step process of connecting to a free WiFi network on an iPhone? I'm not sure if I'm doing it right and would appreciate some clear guidance. What do I need to do after I swipe down from the top-right corner of my screen to access the Control Center? Also, are there any safety precautions I should keep in mind while connecting to a public WiFi network? Thanks in advance for your help!