Beat stockfish

If every single person on earth played stockfish once, will there be a chance that one of them beat stockfish (no other help allowed, just the player)

Maybe, but I am not sure.

I don't think that is possible...

no way

to draw is already hard

ok

i played stockfish against stockfish and Stockfish as black blundered (Mate in 21 though)

There are some people, though a very small portion of the chess community, that purely only play against engines and study them a lot. 
If you had some sort of simul where the entire worlds population all played 1 game against the most advanced version of stockfish, and it was a classical game so they all had ample time, there might be tiny handful of people who MIGHT win, if they get the perfect position, purely because they understand how to beat engines.

Also there is a small chance one of the top players like Magnus might snag a win because they are much higher rated.

However the chance of all this going the way i described is very small. in all likelihood stockfish would win every game. It's like asking if every 1000 rated player in the world vsed Magnus would any of them win. There might be a slim chance, but the chance it would happen is tiny. the difference between a 1000 rated player and Magnus Carlsen is just too big.

Thats the same difference between Stockfish and even the highest rated GM's in the world, nevermind the rest of the human population.