I want to take divorce this year. I would like you to suggest me how to prepare for court.

I want to take divorce this year. My marriage story beginned when I came to Poland as student with student visa and then I meet her and we decided to get married. My wife is 13 years older then me. After marriage I received polish card for 3 years and in that time we moved to Netherlands and I have resident card as her family member. In the end of November our twin daughters was born. In March we gonna have 4th anniversary of our marriage. What more is that in 2020 she convienced me to take also marriage in church but actually I am not christian either catholic so I did it only for her.

I would like that process will go fast without any complications. Currently I am also in another relationship with girl also from Poland and we are just waiting for marriage finish to be together so I would like to put case in court between June and August after girls will little grow. I would like you to suggest me how to prepare for court. Which documents I should to prepare? What can be nice to mention to finish that marriage? How children influence on case? And if after divorce, as I am from India, I can stay still in Netherlads when I have job and home? Also how long can it take to finish everything?