im new here and i have a pig% speedrun that i want to submit but i dont know where to post it on here

Go to the leaderboard for whatever game it is, and click submit run.

Hello hobjoblin and welcome! If your speedrun is for an existing Category in one of the Games on the site you simply go to the respective page of the game and click Submit run, as Pear said.

If the speedrun is for one of the Games already on Site but the Category for it does not yet exist you have to contact the moderators of the game. You will find them all on the respective page of the game.

And if your speedrun is for a game that is not on the Site at all yet you can request it to be added here: https://www.speedrun.com/requestgame

Hope you have a good day :)