You appear in the office of the academy director. After a short confusement you decide to look around. To pass the first event you need to examine 5 objects: wardrobe, table, bird, fireplace and the door.
During the night an owl will appear, read the message. In the future, if you get a message or a package try to open them immediately, so the story progression won’t get stuck.
After you read the message Snape will enter your office, talk to him. The day will end afterwards.
Every new day examine the wardrobe (you can do it once a day). This will allow you from time to time to get various items to use. Aside from that you can’t really do anything during the first days so feel free to doze off.