Sound and image are shifted after importing them into Adobe Premiere
If you recorded using the IPhone, it could be due to the fact that the camera records in a variable frame-rate or VFR. This means that if the camera can't record a frame, it will skip it and so that second will have 59 instead of 60, and sometimes this can be very bad for longer footage and older phones. After time it those skipped frames will add up. 

Adobe programs don't like variable frame-rates, I believe this is because they are "Professional" and don't think they need to support this feature because it's only a problem with low level cameras and recording software. They intend all footage to be Constant Frame Rate or CFR, meaning there is no skipped frames at all. When it comes into contact with VFR they essentially stretch out the footage and frames to fit the entire footage time, while keeping it at a CFR. 

I personally don't know any amazing way of fixing this, other than re-compressing it using a program like Handbrake. Using handbrake you can change the footage frame-rate to a CFR. Handbrake is my solution, however it only supports H.264 and H.265, etc so it can be limiting. If you want to make sure you don't lose quality, try finding a different program and rendering it with a lossless codec.