To post this blog, I logged in to my Weebly account, went to my Blog page, clicked Post Blog, typed blog title, dragged the Text box under the title, wrote this text, then clicked Publish Live.
Anne, only the person with login info can make a blog post (me for this site, or you and me for your site). Once the post is made, any site visitor can make a comment. You can have categories for each post. This post is in the Second Post category. If you leave a comment to this post, I'll receive an email letting me know. Thanks, Clive