Blogspot has an excellent interface but with security it's a bit complex. Here is what I've found out over the past few days. In order to comment on a blog posting, you need to have an account on Google or elsewhere. I'd recommend Google and you can create a few account, with a nice set of features, at Google here. Remember your ID and password. You'll be asked for those when you Comment.
Following. You can follow this blog by clicking on the "Follow" button at the top right of any blog-page. Again, you'll be asked for credentials. I'd recommend your Google account information here as well. When you follow a blog, you will get updates of what has happened on the blog that you follow. If I post a new entry, that will show up on your Dashboard.
As an interesting note: I've created the blog, but it is not automatic that I follow my own blog. When I, too, click follow I get an update of what has happened on my blog on my Dashboard - no alerts are sent. Your Dashboard will be available to you once you start following a blog. It's possible to get updates for several blog at once, as happened when each of my students had their own blogs.
But the general "tip" here is to have a Google account (or Yahoo -- you'll get a choice) at hand to use when you want to comment or follow this blog.