I'm sure you've seen this explained on the first page. Hogwarts is a Role Play by message board site dealing only with the Harry Potter world. Our goals are to have fun and briefly visit Harry's reality with our imaginations. In other words, each character writes about their experiences in Hogwarts as they are happening in post form so that other characters can continue the story. This way no one will really know what is going to happen, because each character adds something new to the story.
Creativity is encouraged.
Well, being here is good, but other than that, you should post on your common room board. You could then go to the Great Hall and have dinner or post an adventure there. One of the most important things if you want to pass first year, is to go to each class. The students will help you out with the current lesson, and so will the teacher. Treat them as you would any Hogwarts professor.