Seeing as I was in a similar position a few years ago just going to add my thoughts/experiences here.
The way I got started and got my first student was to go down to the my school at the end of year 12, and talk to teachers and see if they could tell their students during the step up from year 11 -> year 12. In the end they asked me to make a flyer which they handed around to them in the step up week. Which is similar to what Stick is doing, don't be too pushy but if you got along with the teachers then most likely they'll put a good word in for you and help you out there.
Stick, aren't you afraid that maybe those students won't like you? I don't know, I personally wouldn't want my peers to be my students, just in case something goes wrong.
If they don't like you in the first place, then they won't really come and ask for tutoring, if you start and the don't turn out liking you then the worst that can happen is they don't do another session with you, which if the sessions aren't going great or the student isn't getting anything out of it, then isn't a bad thing if you don't continue with them.
At this stage your main source of students will most likely be from your school, you don't have experience in tutoring yet so you need to have someone to put that good word in for you, i.e. teachers. In later years you'll get more students from elsewhere as you'll have a bit more experience. Also you'll get some really keen students looking for tutors not, but most of your students will come a little bit later. More towards the start of next year, and you'll notice a peak of pm's or emails about tutoring a few weeks into the first semester after everyone gets their first sac result back

One last thing, in my first tutoring session, I was nervous and absolutely blew it. As a result I didn't end up tutoring that student again, but if it doesn't go well at first, don't give up. After I got another student and got into the rhythm of it, it started going well and the student started to take more from each lesson. You might not get it right on the first shot, it's about building up experience and confidence in tutoring, now I'm fine right off the bat most of the time.
tl;dr Going back to the school and seeing if your teachers can help is a good thing, also don't get down if the first session or so doesn't go well. Keep at it for a few and try and build some confidence in it.