Aside from the advice above, I would say get a job.
Find a job that will teach you to hang drywall, lay tile, lay carpet, frame, install baseboards, fix toilets, etc etc you get the idea... This will not only give you some skills on how to do these things, but will give you an idea of what to look for (and what you don't want) when searching for a property. You may even find a rehabber/flipper to do some work for off craigslist (sweep floors, paint, sand drywall, etc) - any luck if you work hard they may mentor you.
Since you aren't able to get a loan or sign contracts (without your parents, which is great that they support you) I'd focus on things you can do, such as education. Learn the ins/outs of every strategy you'd like to try - you mentioned possibly flipping, but mostly renting. Figure out what area you want to focus in, what housing costs are, what rents are, etc.
I've seen 16 year old's that are smarter than some 40 year old's, so that makes no difference. It only matters how much ambition and knowledge you have. Close a deal of your own at 18, then see who thinks you're a joke.
cheers
marc