I would suggest getting the m4 conforming karate suit from DAZ3d.com

https://www.daz3d.com/karate-gi-m4

this set uses morphs and/or movement handles to adjust the loose part of the tunic over the legs, but will be much less work for you than dynamics. I can walk you through using the set, and using poser's morphing and smoothing brush tools to adjust the cloth for each pose.

There is also the possibility of using a new tool for poser that just came out called "VWD Cloth & hair", which allows you to dynamically drape any conforming clothing but it's not a tool for a novice. I've already experimented with my m4 hakama and kimono .. I need more practice... it didn't come out well lol

Lyrra