Hi Gall
welcome here.
For delete your post, you should modify it and wait for it to delete itself, in about 5 seconds. But you can do it just if you posted your post recently .After one hour or more, it's too late and you can't modify your post . So, the only thing you can do is to report it, but you can report a post, just if not appropriate/abusive/rude.
Try to see if you can still modify it
. Hope I helped you.