The term "exporting" is analogous to how it is used in the real world... You are sending the data away from where you are to another place. The analogy breaks down in that it is a copy of the data, unlike exported bananas that are no longer sitting on the dock in South America.
The idea of exporting computer data usually implies the transformation of the data. For instance, you can export a Word file into a PDF file. Once the file is exported as a pdf, it can no longer be brought back into Word for editing.
The opposite of " Exporting" is "Importing". If you are importing, again there is a transformation of the data. Why would you care? well, importing is not perfect. Just like translating froign languages, sometimes, details can be lost in translation.
Another pair of terms that are commonly used for the same idea is "Upload" and "Download". You "Download" data from a remote computer to your PC or you upload data from your PC to a remote computer.
I your case, I assume that you would "Export" your blog data from the website where you are hosting your blog, to your own computer ('s hard drive) .
For a more specific answer as to where to go from here, you will want to describe what you want to do with your exported data.
Do you want to publish it to another platform? Which one?
Do you want to print it out so you can let your grandmother read it?
Are you backing it up so that you can restore the blog in the case of data loss on your blog's host?
It sounds like you may want to re-work your writings and publish them as a book or article.
What tool would you use to edit? DO you know where the data is kept on your PC? What format will your publisher want to recive the work in? How will you get the finished work to your publisher?