ListLevel Object

Each ListTemplate object has a collection of ListLevel objects.
The ListLevel object is the object that defines the actual formatting of the ListTemplate object.
For single level formats the ListLevels collection only contains a single ListLevel object.
A multi level list may contain up to nine levels.

listlevel = ActiveDocument.Paragraphs(2).Range.ListFormat.ListLevelNumber 

Does changing "the number style for this level" to (none) - make the level hidden

List Level means the level in a numbering outline: so in Figure 1, the first and last paragraphs would have no list level, and the middle two would usually have list levels of 1 and 2 respectively.
You can get the list level that has been applied to any list-numbered paragraph using the ListLevelNumber property; for example:

MsgBox Selection.Paragraphs(1).Range.ListFormat.ListLevelNumber 

A paragraph that has no list numbering applied returns 1 - whereas it really ought to return nothing or 0, or 10, or 9999, or something that indicates that it has no List Level - but certainly not 1. This is a bug. So to distinguish unnumbered paragraphs from paragraphs which genuinely have a List Level of 1, you have to use something like:

If Selection.Paragraphs(1).Range.ListParagraphs.Count = 1Then 
    MsgBox Selection.Paragraphs(1).Range.ListFormat.ListLevelNumber 
Else 
   MsgBox "Not a numbered paragraph" 
End If