Step 1;

To animated your text on a path first create your text using the text tool.

Step 2;

Now with the Text selected, click on the Pen tool and then start drawing your path that you want the text to flow across.

Step 3;

Now scroll down the Text parameters till you see Path Options.

Step 4;

Click on the drop down menu and select Mask 1, now your text is aligned to the path of the mask.

Step 5;

Adjust the First Margin parameters to watch your text move along the path.