A platform on which to have a blog?
"kingsweb" made a couple good suggestions. Blogger is a hosted solution that is popular. WordPress offers a hosted solution too, or many templates for self-hosted blogs. Or there is TypePad. Or many others. Some hosted blogging solutions tend to particular themes.
Or are you seeking sites on which topics related to blogging are discussed? If so, you could raise some of those questions right here on Daniweb. Or there are many forums whose main theme is the discussion of blogs, blogging, blogging technologies, etc.