What a cutie! Thank you for giving him a good home. What is his name? He looks like a full Yorkie to me. My boys are long legged, tall. We even have a club here on YT for "Long Legged Supermodel" Yorkies.
As DvlshAngel wrote, buy a harness ASAP. Yorkies have delicate tracheas and should not have leashes attached to collars.
You are wonderful for thinking about behavior classes. Obedience and trick training using positive reinforcement are great ways to bond with your little guy.
If you haven't already, establish a schedule for meals, potty breaks, playtime, etc. Having a routine is comforting and will encourage good behavior.
My favorite hair products are Biogroom and Coat Handler, both of which I order online. Visit the grooming section for more suggestions. Just be sure to use a good tear free shampoo on his head.
There are many good food choices: Wellness, Merrick Before Grain, Orijen, Acana, Fromm, Taste of the Wild, Castor and Pollux to name a few. Everyone has their favorites.
Congrats on the new addition to your family!