In addition to what others have mentioned, try to have some kind of resume typed up. If you are just starting out, include activities/clubs you participate in, or if you did babysitting, include that. If you've had previous employment, include that instead.
Since transportation is an issue, walk or take the bus to locations where you'd be able to get to the job easily, because once you get the job, that will be how you get there, and it should be timely and reliable. I found to get a job (not necessarily a career), in person applications worked better - typically stores or restaurants may have signs they are hiring, then fill out the applications. May want to consider things like restaurant cleaning crew for more upscale restaurants or hotel/motel cleaning crew if there are any of those nearby.
When filling out an application - like was mentioned above, dress clean and be well groomed (bath, brush teeth, comb hair). When you ask for the application, be pleasant and smile. When you shake someone's hand, have a firm grip - not a wet noodle nor a vice grip. "In person" job hunting is a great opportunity for you to sell yourself - so be honest and confident, even if you may not feel it - the confidence and pleasant attitude in person goes much farther than 100 emailed applications.