Firstly let me say congrats on buying the best mainstream mobile device currently in existence.
Here's how to do shape matching:
First, you need to check and make sure your phablet is updated to ICS 4.0.3/4.0.4. To do this, navigate to Settings --> About Phone. You need to look at 'Android Version' and you want it to be 4.0.3+. If it is less than this, e.g. 2.3.6 you need to update it before you will have the 'S Note' app which allows you to do the shape match.
If your phablet is already up to date, or once you have updated it, find the app on your phablet labeled 'S Note' and launch it.
Create a new note, choose a template. Now, directly above your note (the part where you can write/draw) there will be 10 little icons. Click the third one from left twice (the one between the pen icon and the 'T' (text) icon) and you will be presented with a menu labeled 'Productivity Tools'. Select 'Shape Match' and your ready to start drawing auto-corrected shapes!
If this helps, please click 'thanks!'.