Remember what a wise man once said...
"that the device the SO is holding is not a timer....it's a MIND ERASER!!!"
I find that sadly true.... usually before the stage you think about what and how you are going to run the stage... but when the timer go off... you forget everything hahhaahahahahhaa
Just a suggestion from another beginner but if it is in the budget buy a timer for your practice sessions. One of my big issues the first couple of matches was when the timer went off my brain just froze and did a data dump. I even use the timer on my dry fire drills now and stop the time by tapping the timer. That beep is not as intimidation as it was and as someone said in a article I read if you can't measure it you cant improve it. Good luck