[ we make science jokes, periodically ]

Roaming the vast Minecraft world on your own gets lonely. If only you had a friend who kept you company... Well, you're in luck! Here's a code for a little buddy.

Step 1
Delete the on start and on chat command blocks.

Step 2
Add an on player walk block.

Step 3
Add a teleport to block inside the on walk block. 
Change the position parameter to read ~-2 ~0 ~0

A little thing on parameters:  

And you're done! Now you've got a lil buddy tagging along on your coding adventures.