I am making a game and it has a sword, but I don't know how to script in gml.

this belongs in the scripting subforum and not support

download this brk file for a swords script:
https://cdn.discordapp.com/attachments/550139861311553546/550139897470517258/sword.brk

however sword fighting games in BH are trash and boring and you shouldnt add swords to your games

it honestly depends how you make it