When you pause a game if you use Unity you set the TIme.deltaTime =0f; just add in the menu script on void Start {Time.deltaTime =1f;} this works only in unity
Just seen this...
Okay so you want to have "using UnityEngine.SceneManagement;" at the top of your script.
To restart the active scene: SceneManager.LoadScene(SceneManager.GetActiveScene().name);
To load a different scene in: SceneManager.LoadScene(scenenumber); where you find the order of the scenes in the build settings. You may need to add active scene to the build list, but that's just one button click at the bottom right of the box where you're ordering the scenes