Making Layers visible when activated?

Hi, I am a bit new to coding and unity just so you know..

What I want help with is to make the camera to view different layers when I tell it through the game! For example: When I press the pause button in game the player can´t move and I want the pause button to dissepear and a resume button and a Menu button to be visible and when I press the Resume button the Resume and the Menu button dissepear and the Pause button comes back and you can play again!

So basicly a pause menu.. I´ve made it so the game pauses and plays the way I want, now I only whant to make the buttons show when clicked with the mouse..

So is there any way to make layers visible when activated and invisible when deactivated?

(Sry if it might be hard to understand, I´m from Sweden :P)