Normally putting the URL of a pdf on a line by itself doesn’t display the pdf on a WordPress page, and if you use the add media button and paste the URL for the pdf into the URL field, you get a link that will open the pdf, but the pdf does not display on the page itself, e.g.:
But by installing the free Embedly plugin and pasting the URL of the pdf on its own line in the page editor, the multipage pdf file should display right on the page:
And here’s the same document using an alternative plug-in called Embed Any Document.
You can embed pdf files from most anywhere, for example here’s one that is on a Slack channel.