How do you set up Siri?

Try the steps here

https://support.apple.com/guide/iphone/ask-siri-iph83aad8922/ios

Hello donkeefe,

The how of setting up Siri is driven by the iOS version you have rather than the iPhone model you have. This info is relevant for iOS 14 but you can see instructions for previous iOS versions using the User Guide I have linked below.

Ask Siri on iPhone - Apple Support

"Set up Siri

If you didn’t set up Siri when you first set up your iPhone, go to Settings  > Siri & Search, then do any of the following:

• If you want to summon Siri with your voice: Turn on Listen for “Hey Siri.”
• If you want to summon Siri with a button: Turn on Press Side Button for Siri (on an iPhone with Face ID) or Press Home for Siri (on an iPhone with a Home button).

To change additional Siri settings, see Change Siri settings on iPhone."

I hope this helps.