So the idea is, im gonna make a 16 fighter bracket style tournament where 2 fighters meet at the middle. and its all gonna be 1 on 1 fights. so for the fights i was wondering if i wanna make a fight between a player and an npc at roughly the same strength, can i just use a player character sheet or is there a better tool for this? like all the rest i have figured out pretty much, but this. not so much

PCs generally have fewer HP and deal more damage than a monster does. A fight between two PC-types can be very swingy.

Meanwhile, monsters are generally designed to stand up to multiple PCs attacking them for a little while, so the combat may not work right there, either.

Additionally, if the PC is going to get a rest before the next round, they can let go with all their best abilities.

You're probably going to have to run some test fights yourself to see what works for your purposes.

What outcome do you want from the tournament? Does the story stop if the PCs lose? For my money the organization of the event isn't so important as knowing what to do when there's a win or a loss or a draw.

Does this tournament allow magic and/or magic like abilities. If the answer is yes you will never find a good 1v1 balance using character sheets. If you want to make your life simple just make a stat block for the NPCs. Give them enough hit points to survive 2-5 rounds of combat and 3 cool things to do in the fights. 
If your players are all participating and will fight each other you will come across some serious problems depending on classes and levels. Monks will stun lock most for easy wins. Paladins will Nova smite for one hit/turn KOs. 

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So I've actually already had a 1 v 1 sparring match between to players and it actually went pretty well, its also pretty early so they cant do too crazy stuff at this point. its also the first major arc in the story and such.

Also the idea for the tournament is pretty much anything goes since the country's philosophy is, "if it goes in a real fight, then it goes in a tournament"

but ill definitely take into account what tips you've given. so thanks for that.

so the idea is its just a tournament fighting for a price and since player can fight each other that just means they have to spectate till the tournament is over. I'm mostly using it both to create some fun and interesting fights as well as for setting up some major characters in the over all story, its still just the very beginning of the story

aight thanks for the tip. also the idea is that its just single fights, its not more than one fight, though i can see the confusion as I did say it was a "standard" bracket style tournament, but ill definitely try some test fights, that was a great idea 

We've had fun with tournaments in the past. Our party had one entrant since it was his deal. But the rest of us got to play as the other fighters in the tournament for the fights, so it actually became fun for everyone, plus betting on the side. We just got a PC handed to us by the DM with a good ring name and a bell ring. The DM ran the npcs that had special abilities, the rest of us were just running monks as long as we were still standing. Lots of fun.

so i homebrewed some golems designed Specifically to kill members of a cretain class, some examples

• monk-ripper. immune to the stunned condition
• paladin-ripper. has tentacles so can attack at a range
• barbarian-ripper. getting to close to it subjects you to Calm emotions

it might be to in-your-face, but i think it works well