School

School is a location in part 2 which you can select from the Dining Room in your Home on weekdays.

Interactions at School
Before and after school you get 2 options

Before School
1). Choosing the "weird girl" you'll interact with Tracie. Once infected you will be able to "Follow Her" and eventually "Participate" which takes you to the Sanctum and let's you fully infest Tracie.  Once on Tracie's infest screen she has a special event "School Bathroom" in which we learn that her parasites have control over her ability to pee.  Tracie, who is naturally submissive, is surprised but does not reject this change.  The ceding of her control causes her resistance to fall to 0 meaning she will never reject any parasites introduced into her body.

or

2). Choosing "go to class" you may get the event where a fight breaks out and you have to choose to intervene, ignore or "Cat fight" join in. By joining in you will be sent to the school Nurse. If you have not infected her she may remove detected parasites. If you have infected her you will be able infest her further.

If Claire is infested sufficiently, going to class will trigger a multi-part event where she slowly infects the other students (who we are reminded are DEFINITELY 18) and turns the males into females. This progresses to the point where class devolves into a daily parasite breeding orgy with Claire joining in.

After School
1). After school you can go to the teachers lounge and interact with Claire, if she is not there this gives you the chance to infect the room, then go home.

or

2). Go to Steve's house and attempt to infect him and his parents.