Display/Edit Timer on screen with editable GUI and events after time is up.

Hi! I am currently trying to make a block that triggers a timer upon stepping on it. I am thinking about having some sort of timer that is shown to the player that can be changed when right clicking on the block. If they go to this specific block, the timer stops and the event isn't triggered. However, if the player doesn't go to the block in time and runs out of time, it triggers the certain event. Bonus if it triggers something to warn the player if they have 30 seconds or 10 seconds, like changing the color at a certain time etc.

I am brand new to this procedure system so setting it up from there isn't my strongest suit. Thanks!