If you want to see who has visited a page, you'll need to do two things:
1) Add the tag to the page in the site dashboard
2) Make a stream to see the visitors with the tag
Add a tag to your page
Go to the "Site Tagging Settings"
Paste in the URL you are wanting to tag, click Search, and press the blue pencil when you see your page highlighted.
Select the Tags tab, type in what you want to tag visitors, click the green tick to add it
Then "Update Page".
Now your contacts who visit the page will be tagged. :)
You can then make a stream to show everyone with this tag.
Choose Contact, Tags, With the selected tag, *yourtag*
(If you don't see your tag in the dropdown, refresh the page and try again)
Then click "Add Rule" (you can then add other rules, e.g. if you want to only show the visitors who also have the tag "Identified")
Once you've added all the rules you want, click "Save and Continue"
Then choose the name of the stream, and create/add it to a Group (or 'dropdown') to organise your streams.
Now save it, and you're done - refresh to see the results :)
It will show everyone who has visited the page in the past, and continue to show people who visit in the future. Call if you need, on 0161 414 1080 or email firstname.lastname@example.org