OK I am 13 and you am going to take an american red cross class I need advice on getting a job, keepinng a job, dealling with kids anything!

Look within friends and family and people your parents may know from work and church.

Fr_Chuck is right... start with people you know. You'd probably feel more comfortable with knowing them, your parents would probably feel more comfortable with knowing them, and then you can build references so they can tell people they know about what a great job you do.
You might want to see about working as a "mother's helper" as well. This can give you some good hands-on experience of taking care of, and interacting with young children while the mother is still at home taking care of things around the house. It can help to build your confidence and you can ask questions and gain ideas from the mothers you are helping before taking on the job of watching children on your own.