What can I use to debug high ping causes?

I’m having difficulties determining where or what specific script is causing high ping in my game.

Is there any tools or things I need to know to find this out?

A really simple way is to launch the game using the client and not in Studio, then press F9 and select the scripts option. There will be lot of info in there, mainly core client items, but look for anything that has either higher than usual (by comparison to other scripts) Activity and Rate.