1) Make an intro video for your homepage that is 30 second to a minute long. First talk about what kind of things you talk about on your channel ... then who you are ... then tell your release schedule ... and then do ONE call-to-action and that is for them to subscribe. Don't monetize your intro video. The intro video is an ad for your channel. Don't have another's ad hurt your ad.
2) Take viewers on a tour of your city and county. Title it "Tour of [your city's name]: [landmark name]". Make these videos short and sweet. Sweet as in cute. Try to be funny yet informative. Do one for every landmark in your city and county as well as unique places in your city and county.
3) After you've done every landmark in your city and county, email your local media (newspapers, radio stations, and TV stations) by sending them a press release about you and your channel. Stress that you're a local girl and give links to your best local landmark videos. Newspapers, radio stations, and TV stations are ALWAYS on the look out for "local color". If you get on a radio talk show, try to be funny on it. The more funny you are, the more likely they'll ask you to come back again.
4) Make up a flyer. Use yellow paper. Have tear-off tabs at its bottom that has your channel's name and its YouTube URL. Post it everywhere you can in your city. Get a map of your city and mark on it where you've posted them. Once a week, revisit those locations on your bicycle and replace missing, all tear-off tabs gone, torn, etc. posters.
5) Collaborate, collaborate, collaborate. Contact channels who have about the same number of subscribers as your channel has at that moment. As your channel grows, contact bigger and bigger channels. Always suggest a specific activity to do with them. Never just that you would like to collaborate.
6) At your school, start a YouTuber Club. Talk to your teacher about creating it. It is for all students who have or would like to have a YouTube channel. Meet weekly. Help each other. Collaborate with each other. Appear in each other's videos. Do skits. Have a group discussion video. Make cookies together. Brainstorm, brainstorm, brainstorm. But most importantly of all, have fun.