how do you delete old posts that you made in the past few weeks? is there a way to do that?

You can only delete posts that haven't been replied to. Deleting posts is frowned upon because it makes the remaining content less useful. If you're not comfortable with your words staying up forever then you should just not post.

I'll repeat what I posted on one of your threads:

Please DON'T delete your posts once you're done with the question. It makes this useless as a resource for others to learn from. It's a selfish abuse of this forum to take something from it, and not give back.