Read my previous comment, click edit, delete the title and the written introduction, but you can instead type "test" in both sections, unfortunately no one can delete a post fully, and you can't delete the very first hashtag, so it will just be a blank "testing post"

don't worry too much, just keep posting and move forward

but if it really bothers you then start a new page, you can check my other profile @peacemaker, I messed up that account my first few posts, but i recently just started using it again. you can take a look and see what I mean