Squiggle,
Does your school teach woodworking? If so the shop teacher will be happy to help you. Just tell him you want to do a "W" splice and he will walk you through it when the time comes. In the mean time, strip the rest of that bark off, seal up the ends with a few layers of latex paint, and set it in a corner to cure for a year
If your school doesn't have a shop program, you can use the next year to work on a couple board bows, buy a good hand saw and a couple clamps and the splice will be easy-peasy.
When I was your age I was playing around with rocket fuel. This hobby is safer.