Hello, i cannot connect my New iPhone with jbl speaker . Please help

Pair your device with a Bluetooth accessory

1. On your device, go to Settings > Bluetooth and turn on Bluetooth. ... 
2. Place your accessory in discovery mode and wait for it to appear on your device. ... 
3. To pair, tap your accessory name when it appears onscreen.

Pair a third-party Bluetooth accessory with your iPhone or iPad

This may help you --> How To Connect JBL Speakers To iPhone - Ultimate Guide