Don't worry about making money with photography right now, work on your portfolio and concentrate on learning. Having went back and looked at some of your stuff - and seeing you wrote you started about seven or so months ago - there's just no need to rush. Trying to worry about making money is not what it should be about at that state (even if you were 52 years old and just starting 7 months ago). Should be learning, learning, learning, followed by learning some more.
Now, you've already taken the first steps and are on this board asking questions, you're out shooting what you can it seems (hockey/surf I saw), and you're thinking before acting, putting in some work and research, you're FAR ahead of many others!
So, first step is keep shooting - go to your schools games, any sport, learn, try new things. Every time you go to a game make sure you are researching the game, i.e. search around online for some shots and see what pros are doing. Go and practice different angles and work on exposure, timing, etc. Learn!
You start getting proficient, then you can set up an account with Smug Mug or Exposure Manager, any of those services. First thing you need to remember though when selling someone a product, like prints, is that you're providing a service and need to supply quality no matter what your age. Personally with any image that goes online for that I will NOT post it unless knowing it will make a good looking poster print. Think through their eyes, not yours, yours are biased as it's your photography.
You also have to really research your area, price wise and what to cover. Prices are not pulled out of the air - you have ten pros in the area charging $10-20 for an 8x10 and you come in not looking around and start charging $5, well you just not only undercut yourself but all the pros around you. Also, stepping on toes is a really bad idea - you have to find your gigs and land the job, many newer photographers will undercut and do any shady thing they can just to land a job, no matter who it hurts or even if they can deliver on it. Do your homework and know what you do will come back around on you.
Once you have a site set up you promote yourself, give out cards, work with the teams, etc. Honestly I hate the suggestion that you approach teams saying you'll give x-amount of each sale back to them, it's common nowadays in some areas but not all. I never bring that up, if they do I tell them straight out it's fine but I have to charge more if you want a percentage back because there's cost of doing business involved. Not one league I do that with, besides one T&I one year, never been asked. It may not be common in your area, so again it's the homework - do it, research what the others are doing. Not just in your town, but 30 mins to 2 hours away, look around.
Questions to ask though...
1) Is there a school photographer already, will you be stepping on toes?
2) Does your school allow the selling of prints? Oddly enough, some do not.
3) Is it seriously something you want to do or just a hobby you want to make some money at? IF it's about the money, you'll make more getting a part time job after school somewhere, print sales are TOUGH! If it's about establishing the ground for doing it down the road the long haul, it's going to take a lot of work.