Hi i am new and i don't know how to start a speedrun please tell me how do i start

This is a very vague and broad question, we need more information on what exactly you need help with.

Are you having difficulty submitting a run to an LB on the site? Are you looking for more information on what equipment and software you need to run record runs? Are you looking for game recommendations for some new games to run?

If you can provide any more information the helps clarify your question, I'm sure someone here would be happy to assist you or point you to a thread that can help you.