my phone has moisture under my too back cameras and the selfie one. Is there a way to remove it?

check inside the SIM tray aperture for a red water ingress marker. If red there is a chance the phone will stop working eventually. Backup your data and safeguard your photos.

All you can do is hope it dries ok but you will be lucky if it does

If you see a liquid-detection alert on your iPhone 

About splash, water, and dust resistance of iPhone 7 and later