separating video and audio

First time user here. I just took a one minute video of a restaurant general manager speaking directly into the camera.  I also took some photos of food and the interior. I don't know if I will ask this question in the correct way.

I want to edit in photos at certain spots within the video.  I don't want the voice/audio track to be interrupted.  I just want the visual to be changed...and then have it come back with the audio consistent with it after the photo is edited out.

I had though the "lock/unlock" icon would be the solution. I got the idea for that via a tutorial video. But when I unlock and then drag the video portion up to another track, the audio moves with it to that track.  That makes the whole video completely disjointed.

How do I edit in new visuals and keep the flow of the audio consistent?