Hi when I power up my P2V there's a non stop buzzing/humming noise coming from inside the P2V, Is this normal?

You didn't specify if you have a basic or upgrade remote control but make sure your Vision Assistant is set correctly.  I'm guessing you have a Zenmuse H3-3D so the noise is probably coming from the gimbal.  Try moving the gimbal control and see if it stops.  You may also want to calibrate and try adjusting the vertical and horizontal limits.

In the Vision there is a tiny fan in the camera, try to shut off camera, and the sound is gone.

My vision has a high pitched  squeal  too.  Its normal.