You might find it worthwhile using httrack if you’re after long-term storage, and don’t want to worry about versions of WordPress, PHP, MySQL, etc. Basically, it’ll download a complete mirror of the URL you specify and all pages beneath it; it’ll also grab the images, and adjust URLs if necessary to make sure they all work wherever you re-upload it — you just let the program run for a while and download everything it can. I did it to my old blog versions here:
https://archived.ryanjohnwilliams.com/v1.ryansgoblog.com/
https://archived.ryanjohnwilliams.com/v2.ryansgoblog.com/
As you can see they look like perfectly functional websites and are preserved perfectly, however they’re completely portable and can be reuploaded anywhere as it’s all static HTML; as a result, anything dynamic on the blog such as posting new comments will no longer work.