Help seamlessly cutting section mid-song

I am trying to cut a 30-second portion out of the middle of a song, but when I do I get what sounds like a tiny skip where the deleted part was – how can I fix this?

I assume you are not professionally involved in education so I moved your post to the Windows board.

Please see this FAQ: Why do I hear clicks when I remove or paste audio, or at the start or end of the track?.