I need help for the Kanji arc...what lv should I be when the Kanji arc come around?

Strong enough to beat wet men in a bathouse...so 69.

Lol This is the first time I will be playing a persona game to the end so what will be carry over after my first playtrought

I'd love to help you out, but I can't quite remember what specific level I was around in that part of the game...I'll just throw out a guess and say you should be in the 30s at least.

"I'd love to help you out, but I can't quite remember what specific level I was around in that part of the game...I'll just throw out a guess and say you should be in the 30s at least.
"

Money, some items, and the compendium

around level 13

On Normal difficulty, I started Kanji's dungeon around level 17 and finished up between level 25 and 30.  (But I am an obsessive level-grinder, so your mileage may vary.)