Allowing only one person to create blog entries on the site [closed]

I have created a website for a photographer that has a blog page on the site. I want only that photographer to have permission to create blog entries to the site. Do I need to make a user login that checks if that user (the photographer) has logged into the site and then allow posts to the blog using JavaScript? Do I need backend languages to make this happen (I only am familiar with frontend technology)? Just looking to be pointed in the correct direction.