Hum Barbie Girl throughout the game
How to prepare for my opponent

Hello
There is a tournament scheduled at my local chess club.
Note that this is going to be my first one . After talking to some players I learned that the person I am paired with is an e4 player . He has played e4 all his career
I am comfortable with all e4 , d4 and c4 .
Good news is I am white 😁
What should I play that hurts them the most ?
Wait - The tournament hasn't started yet, and you already know who your first pairing will be and your color?
How old is your opponent, and how long has his "career" been? What is his rating compared to yours?
Play whatever opening you want, but if I were playing him, I'd play e4. If you beat him, great. If you lose, ask him to go over the game later. It would be a great chance to learn something.

It is not really a tournament but a fun match or league Whatever you feel like saying it
I am not rated but their online rating is same as me
Further , It will be my first Official game so I think winning it makes sense 😅

Google them. Find out their Chess.com and Lichess usernames. Look up all their history of tournament games.
It's not enough to know that they play 1. e4. Figure out exactly what they play. Also, you're playing as white, so you're only concerned with how they play as black. How do they respond to 1. e4 and 1. d4?
Let me give a more specific example: here's a line I prepared against a 1600 FIDE rated opponent in a tournament game, knowing he played the Caro-Kann. I googled him and prepared this special pet line just for him:

Google them. Find out their Chess.com and Lichess usernames. Look up all their history of tournament games.
It's not enough to know that they play 1. e4. Figure out exactly what they play. Also, you're playing as white, so you're only concerned with how they play as black. How do they respond to 1. e4 and 1. d4?
Let me give a more specific example: here's a line I prepared against a 1600 FIDE rated opponent in a tournament game, knowing he played the Caro-Kann. I googled him and prepared this special pet line just for him:
That’s nasty lol

Hum Barbie Girl throughout the game
Come on Barbie, let’s go party. Oh, oh, oh yeah. Come on Barbie let’s go party, oh, woah.
Songs aside, you have three options:
(1) look him up and find what e4 lines he plays and avoid playing them (if he counters e4 with e5 and he plays the king gambit against that, then why play a game he likely knows better).
(2) play d4 to hopefully play a game he is less familiar with; or
(3) just play your standard white openings, confident that you’ll likely know them better than him.
I say #3.
Hello
There is a tournament scheduled at my local chess club.
Note that this is going to be my first one . After talking to some players I learned that the person I am paired with is an e4 player . He has played e4 all his career
I am comfortable with all e4 , d4 and c4 .
Good news is I am white 😁
What should I play that hurts them the most ?