how should i connect phone to itunes

Connect iPhone to Computer / Mac

Settings > Touch/Face ID & Passcode > USB Accessories > [Enable]

You haven't mentioned whether you have a PC or Mac

Use your USB lightening cable --> Resolve USB-related alerts in iTunes - Apple Support

If unable to connect --> If iTunes doesn't recognize your iPhone, iPad, or iPod - Apple Support

For your Mac --> If your computer doesn't recognize your iPhone, iPad, or iPod ...

For your Windows PC —> Troubleshooting issues with iTunes for Windows - Apple Community

Use genuine cable --> Identify counterfeit or uncertified Lightning connector accessories ...

See how to --> Sync your iPhone, iPad, or iPod using iTunes on your computer ...

If you are experiencing an issue not listed here, contact support

For what purpose?

What iPhone model?

What iOS version is currently running on it?