Blogger can be a good choice for many classroom blogs. One of its selling points for schools that use G Suite for Education is that students can log-in by using their school-issued Google Accounts. Another great aspect of Blogger is that you can get a blog started in a manner of minutes. But with that ease of set-up comes some default settings that you might want to change. One of those settings being the privacy settings.
In Blogger you can change a couple of privacy settings. First, it is possible to request that your blog doesn't appear in Blogger's list of published blogs and not to appear in Google search results. Second, you can restrict your blog to viewing only by people who have been invited by email.
Applications for Education
If you use the option to restrict viewing to those who have been invited by email, you're excluding anyone whose email address you don't have. That's not a big problem unless your students have grandparents or other extended family with whom they would like to share their blog posts. A middle ground between having your blog restricted to those invited by email and having your blog completely public is to use the option to remove your blog from public listings and Google search results. This just means that anyone who has the direct URL for your blog can see it, but it won't pop-up in search results.
One last reminder about using Blogger or any other blogging platform with students, always activate comment moderation.
Learn more about blogging with students in my on-demand webinar, Winning Blog Strategies for Teachers.