Be patient and realistic. He's a young kinder.
TWO of my three were High Energy kinders. My girl had challenges all through the traditional school system, and probably would have been an excellent Home Schooled student - but I work full time out of the house. However, she is a straight A college student and does far better in that environment.
My youngest boy entered kindergarten last year, but was a December baby - so entered at 5 1/2. He had initial challenges with focusing, staying on task, blah blah blah. BUT my experience with my daughter helped me realize that it'll all turn out okay. He would also likely be an excellent Home Schooled student, because I can teach him anything and he is a receptive, quick learner. He matured tremendously over the course of the school year and ended the year STRONG! BUT he is an older kinder. He's in 1st grade this year, and we are just feeling out the fist week. He always asks when the next break is - whether it's recess, holiday, Thanksgiving, Christmas, Easter, Summer...
The middle son just follows the rules, learns in the classroom environment and does well in the traditional setting.
I'd say, take one thing at a time. Focus on the most immediate concerns. Trust your instinct. Don't reprimand too much about behavior, but help him understand the ground rules in kindergarten.
Wife of 1; Mom of 4 (baby due 10/1)
Take Care!