Click on Following and join as a public follower. As a public follower, I can see your picture and/or name. Nobody else can access you without your permission from what I understand.
If you wish to make comments, it should be easy. Just go to the comment section under each blog entry and type in what you want to say and some blogs ask you to type in letters that it generates, so you may have to do this.
This is because they want to know if it is a human being or a spam activity, or so I have been told.
I follow quite a few people's blogs and it is great fun. I love to get comments and it is nice to know if people are reading what I am writing.