Hi Hannah, I hear where you are coming from for a 15 year old, other kids can be very mean verbally on the appearance of your hair.
The next best thing to the neglect method is the Twist & Rip (T&R) method, so good choice. If you start now, they will not look all crazy and loopy by June, so you should be okay when you go away with other teenagers you do not know. In fact, they may think it is really cool that you are dreading your hair, just explain to them that it is a journey of growing healthy dreadlocks if they ask.
At first, your hair may feel a little rough due to doing the T&R on them, but dreads are soft, can be as soft as your undreaded hair if you use the right shampoos and no blowdryers on it.
So the best way to start T&R is to let you hair section naturally if you can. That means no more brushing or combing it. You will be washing it every 2-3 days still, using a friendly dread shampoo and never using store bought conditioners. Don't wrap a towel around your hair, just let the water drip off, sway your head back and forth when done showering and gently, yes gently pat your hair dry. No rubbing & no wrapping it up. My tip is to use a towel the same color as your hair, dreads love towel lint.
If you can buy the shampoo from DreadlockShampoo.com, I recommend the liquid form for dreads just starting out.
So if you can let your hair separate naturally for a couple of weeks, that's great, that is the best way, that's what I did first. Within a couple of weeks you will see definable sections of hair. Now before I tell you how to T&R, I should mention that the section of hair, where it meets the scalp, should be no larger than 1 inch. When the sections mature, they will be as fat as where the hair meets the scalp. Anything larger takes much longer to dry when mature. Fat dreads, or congos as they are known by, can take up to 36 hours to dry when mature. So that is why 1" or less is recommended, but the choice is yours.
To do T&R, you will not be going TWIST, RIP, TWIST, RIP, TWIST, RIP, that will give you a braided look and you don't want that. You will go RIP, RIP, RIP, TWIST, RIP RIP RIP RIP, TWIST & so on. There is a video on this site how to do T&R that you can watch to learn how to do it yourself, if you get a friend to help, you can't feel how tight they are doing them, you don't want them really tight. I did mine over 3 days and the arms do get sore, but just sit on the floor with a large mirror and put on the television and start, do as much as your arms can take that day. Then do some more the next. Don't put rubber bands on the ends, they can melt into the hair. You can leave them as they are or you can put beads on the tips. The easy way to put on beads is to use dental floss. Fold it in half, pass it through the bead and make a loop. Put the end of your section in the loop and then pull the dental floss through the bead, it will pull your hair through. If it is too tough on some, it just means they are too fat for that bead. You don't want to damage your hair trying to force it through the bead, so just leave it alone.
If you want your hair to look more like dreads for when you go away, you can wrap them with embroidery floss which you can buy cheaply at dollar stores in the craft section. There are so many colors if you want or just buy it in the same color as your hair. To use this, you will fold it in half & tie it at the top of your section, but not too tight, wrap it around loosely a couple of times up there, and then start coming down your dread wrapping one strand in one direction and the other strand of thread in the other direction, making a criss cross method as your come down. You can criss cross every 1/4 - 1/2 inch. There is also a video on here to show how to do that.
To find videos, use the search bar near the top left of this site and type in key words, like Embroidery thread wrap, or twist & rip video, and click the search button. Other members postings on whatever subject you type in will pop up for you.
I had to step away to make supper for the family, so if someone put up a post already, sorry if I repeat anything. So, where was I?
Essential oils will help keep it soft, and so will Apple Cider Vinegar (ACV) when used as a final rinse for your hair. (1 capful to 5 cups of water & pour over head after washing it, and rinse it out within one minute or right away even, this is a healthy conditioner for your hair) For the first couple of weeks you will not use this at all, let your hair separeate, if you are doing it that way. If ever you wash with the Baking Soda (BS) recipe found on this site, always use the ACV as a final rinse or you hair WILL dry out.
Doing T&R, you will go through a stage of the frizzies, I don't remember how long it takes when first twisting. Don't tie up your hair, let them be free and loose. Don't wear tight hats. If you know someone who knits, have them make you a really loose hat, like a tam to wear if you feel really messy that day. We all have down days about the journey, no matter what age we are. No crochet hooks. No wax. No gels.
I think that is it to get you started, if you have question, you can ask me or post the question and others will help you out. Have fun with your journey, embrace the changes and the crazy ride it will take you on during the first year. It sounds silly, but you will grow from within by taking the journey of growing your own dreadlocks. They will mature 1-2 years from when you begin, and in 3 years will be beautiful healthy locks that will last you a lifetime. Have fun on your trip and meet new people...Peace