Thanks Marius Hai for your comment. In order to not attract too much attention, it is important to have a bus that does not appear in the brightest colours and is parked at places where it is not obvious that it is a sex education bus. But I will definitely keep that in mind when I'm proceeding with my idea!
Thanks Isaac Jumba for reaching out to me. I had a look in the other ideas and they are really great. Also I added a picture as you suggested. I was not aware that it might be helpful to imagine how the SEB looks like. Thank you a lot.