How do I make the document parameters in Altium visible?
You can edit the values by right-clicking, and then going to options->document parameters.

The standard altium template doesn't contain the so called "special strings".
So either you have to add the text manually to the field (e.g. type =Engineer) or you have to change the template so it includes it. 

A tutorial by altium explaining the special strings is given here.

Edit: Alternatively you can go to Design>Templates and select a template designed by altium. Those templates have the special string already placed so you should see the document parameters. 

Edit2: 
The parameters in a fully registered altium still look like this:



It is not the visible checkbox that is used to put them into the schematic, look at the tutorial for more info.