WordPress allows you to add more users to your website, but it’s from the backend only. If you want to allow visitors to register and manage their accounts from the frontend, you might create a custom sign-up, sign-in, and user profile page for them. You also might create some fields for them to fill in their information. If you are using Meta Box plugin, you may use it to do it easily.
Guest Author is a kind of guest account in which the visitors can register and use it to submit a post without any admin permission. This helps you have more content for your site, so it absolutely benefits you. From an order of my client, I saw that adding this is pretty interesting then want to share with you how to do it. Of course, using Meta Box.