In the US at 14 or older you can work but the hours are strictly limited for example:
While school is in session you cannot work during school hours, more then 3 hours on a school day, before 7am or after 7 pm. Because of these limits regardless of how old you look or how mature you act it is difficult to find a job but….
It is legal to work in an:
Office,
Grocery store,
Retail store,
Restaurant,
Movie Theater,
Baseball Park,
Amusement park, or
Gasoline service station
Businesses such as Publix, Kroger's, Food Lion, Sonic, Chic-Fill-A, McDonald's, Winn-Dixie, Krystal's, Dairy Queen, and Burger King along with smaller local businesses that are in the same genre tend to hire those your age.
Fast-food and grocery stores are willing and able to train new employees but........................
Minors tend to have many issues that affect their ability to work such as tardiness, absenteeism, and numerous schedule requests, poor work-ethic etcetera.
I am NOT implying you will have those issues but the fact that many your age do makes it more difficult for you to get an opportunity to prove your worth.
Because of this you must be able to show through words and actions that you are reliable, dependable, punctual, detail oriented, trainable, coachable, punctual, mature and team oriented. You will also need great references since you don't have work experience. Talk to teachers, counselors, clergy, coaches, club sponsors, and directors of places you have volunteered or people you have done casual labor for and ask them about giving you a reference. Get accurate, current contact information for them and ask them to be ready to get calls for references from potential employers.
Remember:
Most businesses are individually owned and operated so it is the owner’s policy and past experience with minors that will determine if they will hire you. Apply everywhere you can, the worse that can happen is they don't hire you.
For information concerning hours you can work, jobs that you can do (there are many others) and work permits for minors (not all states require permits) go to:
http://www.youthrules.dol.gov US Department of Labor
YouthRules!
OR
In every state without a permit you can:
Work in a business owned or operated by your parents
Deliver newspapers/periodicals
Work as an actor/ess in radio, TV or the theater
Caddy at a public course
Work as an umpire/referee in a municipal league
Work on a private farm picking and/or selling fruits and vegetables
Do casual labor (work for an individual in their home) such as pet-sitting, baby-sitting, running errands, tutoring, and yard-work etcetera...