And to Odysseus:
First off, you're in Canada right? And are you part of a unit, or are there any in your area that you have considered joining?
Yes, I'm Canadian, 13 Years Old, there are 2 reenactment groups in my area, that are on the internet, both are British American Revolution groups. One, seems more farb then the other but I don't have many options.
OK, mind linking their websites (just curious)? Do you already have any kit (I'm assuming no)? As for other options, there is obviously the drums, if you haven't tried that already. It really depends on the unit and what ages they accept. Some will accept 13-14 year-olds but only as musicians. Meanwhile, others may have different standards. Are there any events coming up in your area that they will be going to? If so, it's best to get there and speak with one/both of the units there and see what they can do for you (and if you are a good fit for the unit, and if it's a good fit for you).
kpet:
Take in mind I'm not an ACW reenactor, but from my experience in other eras, I would suggest boots first (since they can be hard to borrow, what with needing a specific size and all). Next the trousers (again, do to size issues, it's harder to borrow them). Then a jacket/blouse/sack coat (since this is easier to find a size that you can borrow from someone). A hat last (not counting leather gear items like a cartridge pouch and sling, I don't know about that stuff). Since it's probably easier to borrow a spare hat than anything else.
Expect to borrow a lot of gear when you first start-off!. ALSO: Find a unit before buying anything! They will not only likely have gear for you to borrow, but they can also help you more on where to buy gear, especially if that unit had any specific items they wore (or didn't wear).