Concentration in a classical otb chess tournament

I’m going to play my first otb tournament. The time control is 90 minutes + 30 seconds. How do I concentrate for the whole game, considering it will more than two hours to complete ? It’s my first tournament so i’m nervous . Can anyone who has played in otb tournament share the tips you use?

I think you will find that you will become absorbed in the game and concentration wont be a problem. There is some general advice, think strategically and broadly when it is your opponents turn to move, think concrete variations when its your turn to move. If you find concentration wandering, take a short walk when your opponent is thinking. Enjoy the tournament and reflect on it afterwards as to what you could have done better. This might include aspects of concentration and clock handling. Best of luck.

Good luck!

I mean I have played hundreds of them. Thousands of games. Just play and collect impressions and experience. Good luck!

You wont have a problem at all. With chess the deeper you look, the more you see and the more you want to analyze. You'll find that in some positions there is never enough time!

Good luck! I'm sure you will have fun and especially try to analyze the games after with your opponents. -Bill

Be in good shape is important even if you sit for hours...
Eat and drink some hours before so you have plenty of energy at the event.
Have something to eat that gives energy during play.
Drink coffee or something like that during the game.

I'd lay off the bullet and blitz for a while and actually start playing some longer games if you intend on playing classical games OTB. You are better at bullet compared to blitz, which makes me wonder if you gain a fair number of points by managing your time better or flagging your opponent. Time management is still a factor in classical, but don't expect to be able to flag an opponent.

Be able resolving tactical puzzle during 5 minutes without any distraction, no music, no beer, no phone, no opened Facebook page (Discord, tik-tok....)
Few days later, for 6 mn
then 7 mn...
Until you'll able being focuses during one hour.

If you try to be concertrated fot the first time during your tournament, it will be a failure.

Get a good night sleep. Arrive prepared for deceptions. Remain open minded. It's no time to try something new. Play what is sound. Focus on what you know best. Pace your self. There is no excuse, for playing too fast or too slow. Take the time to discover the weaknesses on the chessboard and of the opponent. Feel the stress of forgetting to write down moves. Even the facial expressions or body movements affect players differently. So expect some to get up a few times during the game. Don't touch the chessboard after you made a move. Wait for them to press the clock. Make sure it's not your clock that is running on their turn. Since someone is paying for a good result, do your best. If you must, consider it work, not play.

Get the job done and good luck.

My first tourney game I rushed all my opening moves because I was so sure I was gonna zone out and forget about the clock and my flag would fall! So just learn to relax (as best you can)...90 min is plenty of time. :)