How did you create the method FormCreate? Did you simply type the code? In this case you still must link your code to the event OnCreate of the form. The first issue is that the Object Inspector cannot find your event handler when you declare it as "public", you must put it into the published section, for forms this is the part of the form declaration above "private" where "Chart1" and "Chart1LineSeries1" already are found:
TForm1 = class(TForm)
Chart1: TChart;
Chart1LineSeries1: TLineSeries;
procedure FormCreate(Sender: TObject); // moved up to here to make the method visible in the Obj Inspector.
private
{ private declarations }
public
{ public declarations }
end;
Next, in order to assign your FormCreate code to the event, select the chart in the form designer, go to the Object Inspector, open page "Events", click on the down arrow next to "OnCreate" and select "FormCreate" from the list (without doing the previous step the method would not be listed here). Now it should work.
The next time when you create an event handler in Lazarus do it the easy way: Select the event in the Object Inspector, page "Events" again, and double-click on the right column of the event name (or single-click on the '...' button). The IDE then inserts an empty method body for the event handler and immediately assigns it to the event. You only must go to the code editor and type in your code.
As for the "plotunit" project, you can download the files separately from
https://svn.freepascal.org/cgi-bin/viewvc.cgi/trunk/components/tachart/demo/runtime/plotunit/?root=lazarus&sortby=rev. I tried with Laz 1.6.4 (I don't have 1.6.2 any more) - trying to compile with you Lazarus you will notice two issues which you can fix easily:
(1) In function Plot() of unit uplot, the compiler will complain somewhere near line 132 about "; expected, identifier BRUSH found" --> just comment out the four lines beginning with "Pointer.", they affect TFitSeries, but are not essentially needed for the rest of the demo to work.
(2) The next issue is in unit main, declaration "const SYMBOLS =...", after "psDiamond": "Identifier not found: psDownTriangle". This is because these enumeration elements did not yet exist in Laz 1.6 series. Just close the bracket after "psDiamond and reduce the upper array index to 3 (instead of 5).
Then the demo will compile.
Of course, you should consider upgrading to a more recent version of Lazarus, the current release is v2.02.