Congrats! I love watching you and Kodi! What do you use for treat rewards? I'm trying to find that "one" tasty morsel but he seems to love everything. Timmy is starting Puppy Obedience this morning, so I'm excited about that.
It's really important to vary your treats. Don't try to find "one best one" or it will get boring pretty quickly. First, you need a hierarchy of treats... low value treats that he'll work for in a distraction-free setting doing known behaviors. Some examples would be kibble, Cheerios, "Charlee Bearz", baby carrots, apple slices... Then a variety of mid-value treat that will work under a variety of training situations. These can be cheese, commercial treats (just make sure they aren't full of nasty additive. almost any treat in the dog food aisle is probably NOT good quality food) you can really use anything the dog really likes. Finally, you need high value treats that the dog will basically stand on their head for. You use these when training in very distracting environments, or training new and difficult behaviors. These can include deli meats, any left over, cut up meat from dinner, boiled chicken breast... let the dog tell YOU which are his favorite.
At the stage of training you are at, you want foods taht are soft, can be swallowed quickly, and are cut up tiny. Many of the high value treats are probably messy, so you probably want to get a "bait bag", which is a small pouch that you clip on your pocket so you don't have a pocket full of drippy roast beef!
In AKC, you can't have ANY food even in your pocket when you go in the ring. In APDT and CDSP, as you can see, you can treat in the ring IN CERTAIN SPECIFIC CIRCUMSTANCES. In APDT, the food must remain in you pocket and you can only treat at the END of a stationary exercise, and the dog has to remain in position. And you have to be VERY careful how you handle the food... if either you OR the dog drops the food, it's a 3 point deduction. In CDSP (which is formal obedience, not Rally-O) you can treat at the end of each exercise, again, the dog must remain in position, and dropping food costs you 3 points.
At Kodi's stage of training, the treats are more a "thank you" for a job well done, so it is less important exactly what they are. I want treats that I can feed to him quickly and get back to work. Since I HAVE to have the food in my pocket rather than a bait bag, it needs to be relatively dry and non-messy. Most of what I use is various freeze dried meat products, paticularly organ meats, which are good and smelly!
He has one treat that is his all-time favorite, and that is "Thinker" sticks cut up into little pieces, especially the duck ones. I have found that I can keep him interested in lesser value treats by mixing some piece of duck Thinkers in... that way he never knows for sure what is coming next. Intermittent reinforcement is very powerful!