First, you should make sure that you are using standard frame rates. If you import the footage and it is showing up as 30.1 fps you should change the frame rate interpretation to either 30 or 29.97. These are standard frame rates. Then you make sure that your Premiere Pro Sequence settings match. When you move to After Effects you also have to make sure that the frame rate interpretation of the footage matches and the frame rate of the composition matches. An odd frame rate like 30.1 usually comes from a mobile device or a consumer camera. Forcing the frame rate to one of the standard frame rates that is close to the original will not significantly change the timing of the video or the pitch of the audio. You should never use custom frame rates unless you are an expert in video formats and compression. Things will just get screwed up.
In both applications, there is a panel for footage interpretation and the composition and sequence settings have a place to set frame rates. If you do not know where to find and change frame rates let us know.