Much of this depends upon what you plan your blog to be about. My blog is largely a personal exercise, where I rant about whatever I want, whenever I want. In times past it was unstructured, but I introduced the Meerkat Muse, to keep things vaguely organised.
My blog is also a standard website, with categories and sections based on my interests and discussions. Whether that will work for everyone will depend on the subject.
So, step one is to decide what your blog will be about. Will it be a personal diary? Will it be about say, gardening, historical literature, civil rights, astronomy, astrology?
Step two would be to settle upon a theme. If you’re using WordPress, there are many themes, but not all of them will suit your subject. If you want to combine a blog with a website, you need to consider how the menus flow. You need to think about how blog posts are displayed as well. Do you want every blog post to be fully displayed from start to finish, or do you want to offer a preview, to save space? If you’re putting together a blog on say, sports, you may want to consider big, bold headlines, whereas something around photography will naturally lean to a theme that emphasises pictures.
It’s worth considering text colour too. Some themes (despite being made for websites) do not lend themselves very easily to standard black text. You can usually change the text colour if you need to. This is a relatively minor detail, when weighed against what topics you want to use your blog for. The biggest thing is to find your niche. Once you have that, the rest will fall into place.