When you log in to Blogger, you arrive at the dashboard, where you can see a list of your blogs. (In your case, you probably only have one, which is the one we set up in class.)
If you want to create a new post, click New Post.
If you want to edit an existing post, click Posts at the bottom right.
If you want to edit the blog settings, click Settings at the bottom right.
If you want to make changes to the blog template, click Layout at the bottom right.