I have recently confirmed my thoughts. I had thought for a long time I may be bi, but I was confused. Now I know I am. Please, somebody tell me how they did it or how I could?

I would suggest you find the first person you come out to be a very supportive person. Find one that you will think will be understanding.
Please realize not everyone will be supportive or understanding and it can be a hard time. It is not right that people can be mean but they are. Do you have any gay/ bi groups in your area you can call for advice? There are some on Facebook and online if not.

Well, it's probably hard to tell someoe that, one questio I have is does your parent(s) know about it, or do you know if they would be fine with you being bi?
IIf so, let them know and then you'll probably have more confidence to let other people know. If I was I that situation, I would think your parents would be the ones you would be the most afraid of telling.

I would think you really don't need to tell anyone until you are ready to get in a same sex relationship with someone in particular. How old are you?

I agree that there is no need to tell people, especially if you are in your teens. It's really nobody's business, and 'telling people' comes out as sort of an advertisement. Our sexual preference doesn't define us.