You're welcome

Is kendo your first (as in, doing) martial art? heh. Welcome to the martial artists' world. Best combination with Kendo will be Aikido though. However... Shotokan Karate is recommended for self-defense. Kendo is not self-defense art, it's offensive art. Meaning to say, in reality, no sword-wielder use sword to defense himself but to KILL the enemy to protect himself/family.

I would say there's no best martial art in this world, every arts have its flaw.

Like me, ii learnt martial arts for future sake. To protect my family & friends & prepare for any unwanted circumstances.

PS: Please learn Kendo from a real kendoka, not self-proclaim senpai/sensei (which usually they see & learn from Youtube. LOL).