How do you delete posts and threads??

Sometimes i put up a thread up asking a question and then i figure it out before someone replies…is there anyway to delete posts?
Its probably obvious but i cant find the button

Edit your post and delete all of the text, including the title of the thread

not working
it says it won’t save unless there are 10 characters typed in the message

I think you can delete your post if it’s not the first post in a thread and there’s no posts after it. I do remember seeing that option for my posts until it stops being the last post in the thread.