Congrats on your first HS game! I hope it was as good as you hoped it would be. The good news, it gets even better from h ere
A common rookie mistake is to ignore the coaches completely, endure whatever abuse they heap upon you, and pat yourself on the back for having a thick skin. I sometimes hear 2nd or 3rd year officials brag that they've never given out a T. Either they're incredible, natural game managers, or they haven't gotten the stones to deal with coaches when they needed to. It sounds like you didn't entirely succumb to this trap. Congrats!
Thick skin is fine for baseball, but in basketball you need to "handle" coaches differently here than you do on the diamond. Some of the things he said and did, I think, needed a better response than just ignoring the behavior. Perhaps, just maybe, you could have avoided the T's if you had handled him better early on.
If the coach walks out onto the floor to ask you a question, walk him back to the sideline and let him know that he's not to be out on the floor. If he does it again, whack him.
He gave you a crap line like "I'm not going to let you take another", I think that needs a response, and not just a "I hear you, Coach." Maybe a "that'll be enough of that."
"Stop showing off"? when you tell him he has to sit? T him again and show him the door. He can stand up all he likes in the parking lot.
2nd T with 40 seconds left? Who cares if there is only 40 seconds left, it's time for this bozo to gain some much needed experience. Send him to the showers.
Just my $0.02