What to do for my first OTB tournament?

My top three recommendations are more practical than chess-related:

1. Stay hydrated
2. Bring snacks
3. Chill out and don't tilt

You'll be just fine!

It is contradictory to play Urusov against the weak and Italian against the strong. Why cannot you beat the weak with Italian? If you cannot beat the weak, how will you face the strong with it?

"I usually get into time trouble before my opponent, any tips to help?"
Do you lose or win in time trouble?
Do you have winning or losing positions before time trouble.
If you win, then you have no problem.
If you lose lost positions, you have no problem either.
If you lose won positions in time trouble, then you should analyse on what moves you spend that much time on and why and then cure that.

#10
Not necessarily. If you are 18 years old, you will go through the 7 games with no particular problems if you are well rested.

And last tip: always be aware that LPDO, yours or your opponent's :)

i'm watching one of your games to have an example to give you some tips.

You can't use 2 minutes and 30 seconds to play 16... Rfd8, or you play the move in 5 seconds or you have to play other ideas. I can understand 16... Qd6 if you have material advantage or if you have a time advantage, i suggest you to look for a pieces exchange or to give to your pieces more mobility.
I think that you have enough knowledge in the opening and i see that you have a good elo training points, amazing your training is the same of a master, quiz are not your problem and i think that you have to study the endgame, you must know wich is your worst piece and you have to try to exchange it for the best piece of your opponent. At last i suggest you to study the rook's endgame, it's the most important endgame in the chess, when i was a novice only and i was in my second or third tournament i had read the book of Averbach on the endgames, i lost a lot of pawns but in the endgame my knowledge was biggest than my opponent and i regain every pawns until i won my games, very rewarding to study and win thanks to superior knowledge!
Good luck 4 your first live tournament!

P.S. When I was still an active player, I brought with me a bottle of water, a fruit juice and a few energy bars!

See? That loose bishop on f8 after 31... Rc7 : attacked two times,defended two times. Had to drop off one way or another :)

@tpr I think it's logical to use aggressive gambits against weaker players who aren't as good defenders as the stronger ones. If it's their first time seeing the Urusov Gambit, I'm pretty sure mistakes will be made somewhere and I can use some theory to crush them even before the middlegame. In that case, it might be a shorter and less energy consuming game than to play the solid Italian game where it might take a longer time to pry open their position. Against stronger players, it's a whole new story since if they defend the gambit perfectly, I might be worse off after all the attacks are exhausted. Thus opting for the solid lines will make sure I don't give away any advantage right from the start.

And yes, I tend to lose games in time trouble when I'm roughly equal or winning. The example by @massimilianoferri is a good one.

I tend to be overly cautious before I play a move, double checking and triple checking for captures and checks. Perhaps this is okay in classical games but I might have to change a bit for rapid. I thought of 16. Qd6 but I didn't want my b pawn to hang and opted for 16. Rfd8 which was kind of intuitive although I spent so much time on it. I was too hung up on looking for tactics that would win immediately. Guess I have to change that.

And I will be sure to look into rook endgames in chess books :)

@kifaru I missed 31. Rc8 unpinning the bishop on f8 and threatening to take on h6. But oh well I had less than 20 seconds left on the clock.

Thanks everybody!

You should play the same opening against everybody, weak or strong alike. That way while playing the weak you get experience and learn how to play your opening better against the strong. You beat the weak anyway, the challenge is to beat the strong.

If I were forced to play different openings Urusov and Italian against weak & strong players, then I would play Italian against the weak and Urusov against the strong. The Italian is such that the stronger player usually wins, because he understands the strategy better and he usually has more experience with it. The Urusov might be totally unknown to the stronger player and might catch him off guard.

@tpr

Hmm you do make sense there after a deeper thought. I will post my games here after the tournament (if there are move notations).