need to blank out words in a document with a pen just bought adobe export pdf how do I do this ? Have I bought the correct product ?

Hi Gillw,

If I get it correctly, I believe you are selecting the Highlighting text tool under the Comments Tool. When you highlight any text using the pencil it brings up the Notes Tab (the rectangle box you are referring above) to add any notes if you want to and this is optional which you can ignore.

Once you have highlighted the text you can save the document which would apply the changes.  Please refer to the help document and follow the steps suggested:  Mark up text with edits, Adobe Acrobat

What you have purchased is Export PDF service, which is to export the pdf file to other format. And what you are looking for can be achieve with free version of Adobe Reader DC and it doesn't require a subscription. Using Adobe Export PDF

Regards,

Akanchha