Hello there
welcome to apple support community. my name is killian and i will most definitely help you through this problem you are having with the AirPods Product. Rest assured, we will try our best to help you :)
So if you can please place your airpods in the case they came with, and make sure that they are charged. then, please press and hold the Pair Button on the back of the AirPods Case until you see a white light flashing. please also navigate to the home screen on your iPhone with Bluetooth on and see if a Connect to airpods notification pops up on screen. it should look like this:

once you have connected, please check the connection by pulling down your screen and selecting the bluetooth option, it should say connected to "{your name's} airpods {Model}"
here is a link for more information : If your AirPods won't connect - Apple Support
To connect airpods pro to iphone: Connect your AirPods and AirPods Pro to your iPhone - Apple Support
to conclude this, i hope that the information i have provided you with has been helpful and resourceful, and i also hope it resolves the problems indicated. if you do have further questions i would be most happily to answer them for you. simply respond to this reply and i will continue to help. other than that, it was a pleasure helping you today and i hope you have a really good day :))
Thank you,
Killian R