>>6602AUSKF has a dojo map for the United States with all of the official sanctioned Dojos, that coordinates with the All Japan kendo Federation.
https://www.auskf.org/dojosBeing good at kendo does not require you to start early. You can start late and still practice. Most of the people in my Dojo started in their late 20s or 30s and some even older, and made it up to 3 or 4 Dan.
For most people, kendo is not a competitive sport, unless you do it exclusively for competitions, and even there, stamina and technique beats brute force. Cultivating good Ippon and good style and spirit is better than just being able to land hits, because eventually you will learn to just not get hit.
>>6603A fellow swordsman is always a friend. Even though your swords are not made of nippon steel folded over 100000 times.