Calibre will work for this, but it almost certainly won’t give a good result. That’s not Calibre’s fault; Adobe InDesign produces exactly the same horrible output from a PDF. It’s just a reality that PDF does not lend itself gracefully to being converted easily to a well behaved EPUB.
Unless you are converting something extremely simple with no inline images or interesting text layout, getting a nice EPUB will almost definitely be a tedious process of fiddling directly with the HTML and CSS with something like Sigil (or Calibre, but it’s not as nice).
Calibre will work for this, but it almost certainly won’t give a good result. That’s not Calibre’s fault; Adobe InDesign produces exactly the same horrible output from a PDF. It’s just a reality that PDF does not lend itself gracefully to being converted easily to a well behaved EPUB.
Unless you are converting something extremely simple with no inline images or interesting text layout, getting a nice EPUB will almost definitely be a tedious process of fiddling directly with the HTML and CSS with something like Sigil (or Calibre, but it’s not as nice).