You mean that you want to hide for example a Sprite when clicking a button?
Then, i assume you have this tree structure:
Then you can use the signal
pressed() and connect it to a function on Main.gd script (can connect it via editor. Go to Node tab, select pressed() signal and click connect). The function created when you connect the signal via editor should look like this:
Is that what you need?
P.S: you can also hide Node2D and anything that derives from it. And what do you mean by hiding a sound file? stopping it from beeing played?