Still can't edit a pdf - what am i missing?

Restarting won't change anything here unless the app has frozen. Most pdfs are basically a flat print of the page, so free readers only let you add things on top - edge lets you type text boxes, highlight and draw, and preview does the same on a mac. To change the words that are already there, word can open the pdf and convert it into an editable document (file, open, pick the pdf); the layout gets a bit wobbly on complicated ones. Editing text in place properly is the paid acrobat.

restart holding the power button for ten seconds first. fixes it more often than anything you'll change in settings.