[edit pdf in pageplus x8]

I have scanned a restaurant menu and saved it as pdf on my computer. I am able to import it as a pdf file but dont know how to edit individual sections on a page. It just selects the whole page. I am new to all this but I followed the tutorial for this. I was able to download and import the tutorial file and select individual parts of that to edit but as far as my scanned pdf is concerned, clicking on imported page onto the workspace only just selects the whole page and not individual sections of texts and graphics.