Living in the Wizarding World (Harry Potter fanfic but it’s cool and interactive)

The station was bustling with life.
All around you are students, new and old alike.
Parents waving goodbye and sending well wishes are around every corner, and you push through the crowd.
Your family already said goodbye and had dropped you off at King's Cross station to go to Hogwarts.
You get to the train and pull your trunk aboard, looking around at the compartments.
While you're distracted with looking for an open one, someone bumps into you.
Who is it? (these are all OC's of mine)