Im really sceard that my mario kart speedrun is too long and I might get in a bad place and I dont feel like submitting it I need help chooseing if its right or wrong

No speedrun is too long. If you successfully completed a speedrun that follows the game rules and is faster than your current time, you should submit it regardless of place. If you don't know if something is allowed or not, send a message to one of the game moderators or make a thread on the game forum. I hope this helps.

Hey man, a pb is a pb. If you're proud of it, it's a good speedrun, regardless of the time :)

Check the leaderboard and see what place you would be. If it’s not last, you’ve got nothing to worry about. If it is, submit it anyway.

Even if you're last place, it's worth submitting. because In the incoming years, seeing yourself improve - quickly rising in the ranks - that is more impressive than submitting a good time once.