First ever job interview at a Dutch M&A boutique, how do I prepare

I'm a second-year student at RSM. Recently stopped applying at larger firms because none of them want second-year students. Started applying at boutiques and got an interview at a M&A boutique with 4 offices of ~10 employees each in Europe and ~15 deals per year for the Dutch office.

I've got all of the listed required skills (DCF, excel, powerpoint, research experience, etc). Could somebody run me through how these interviews typically go? What knowledge is required to be known by heart, and what skills do I need to demonstrate, are there any good things to study or practice with?

My only interview experience is getting rejected at Albert Heijn for a supermarket job at age 14, and successfully interviewed to become a board member at a finance association. So that's nada.