Use a USB cable to connect the iPhone to the laptop
Unlock the iPhone
Tap Trust This Computer if prompted
Enter your passcode if required
Open Finder on Mac or iTunes/Apple Devices on Windows
Select the iPhone from the device list
Use Wi-Fi sync if both devices are on the same network and sync is enabled
Turn on Personal Hotspot on the iPhone if you want to share internet with the laptop
Connect the laptop to the iPhone hotspot using Wi-Fi, USB, or Bluetooth
Use Bluetooth pairing if you want to connect for specific functions
Enable AirDrop on Mac if you want to transfer files wirelessly
Make sure both devices have the latest software updates installed