No paragraphs when copying and pasting from pdf file

Yep. This is normal behaviour, and that'll be the way it happens. A PDF is not a layout format... there is no paragraph spacing information as the text is rendered as vector objects... in fact each line is rendered as separate objects (sometimes several objects) that starts at the leftmost character in the line and ends with the rightmost. In a PDF, a paragraph space/carriage return HAS no object so there's nothing to copy.

Acrobat will allow you to select and copy the contents of those objects (the text) and will do its best to honour the intended spacing, but its not perfect. Your lines will come in as separate individual paragraphs, for instance.

You might want to consider a different workflow if this is something you need to do on a regular basis.

e.g. export the text from the PDF as a Word file or as Rich Text. This MIGHT have a better chance of retaining spacing