I read on another post that you are a freshmen in high school, so unless your parents are footing the bill most forms of advertising are out of the question. These guys above already know that, most of them are just being a smart ass. There are free forms of advertising however, which you will have to take advantage of. Craigslist is a big one: post an ad that sounds more intelligent and professional than the 20 other ones already listed that say "Grass mowed, cheap" or something like that. Repost the ad every 2-3 days or however often CL will let you. Print you some professional looking flyers (you can accomplish this on your personal computer with some effort) and put them up all over town, wherever ppl will let you. Always ask permission before hanging a flyer on someones place of business! Find a website or local printer and have some nice looking business cards made (you can do this for less than 50 bucks) and give them to everyone you talk to. Not necessarily other kids, but try to have intelligent conversations with adults and put business cards in their hands. Do a google search for FREE business listings. This will point you in the direction of local business directories in your area where you can enter your contact info. None of these things are going to get you a huge amount of customers. But they are some suggestions to get you started that dont really cost much. I got my first 3-4 customers from craigslist by the way.