Q:  if I write "Font := Canvas.Font" Font is not a pointer to Canvas.Font, Font takes on the properties of Canvas.Font.  I want to know how I can make a variable that is a "pointer" to Canvas.Font.

In pointers it would have been:
procedure X( T : TType );
var
  vP : ^TType
begin
  vP := @T;
  {both of the following make changes to T}
  T.Size := 10;
  vP^.Size := 12;
end;

what I want is:
procedure X( canvas : TCanvas );
var
   F : TFont
begin
  F := canvas.Font;  {<-- ?? assigns copy instead of reference}
  {I need both of the following to affect canvas' Font property}
  F.Size := 10;
  canvas.Size := 12;
end;

Sorry if it isn't clear ... does anyone remember what a pointer is now that Delphi is here?

A:  The problem you are seeing is that in your context the variable Font is not a variable of a class, or an instance of a class. It is a property, and the assignment operator (:=) is being translated by the compiler into an Assign type operation by the declaration of that property.

For example this code:

  var
    MyFontPtr : TFont;
  begin
    ...
    MyFontPtr := SomeCanvas.Font;

does result in an address being copied. Whereas this code:

  begin
    ...
    with Form1.Canvas do
        Font := SomeCanvas.Font;

results in the following code:

   Form1.Canvas.SetFont(SomeCanvas.Font);

which 'copies' the data in SomeCanvas.Font to Form1.Canvas.Font.

See also pointers and dynamic memory