Motocross Questions? Im a newbie.?

Lately Ive been interested in getting into motocross. I've looked up things about it but I would like to get an experienced rider's thoughts and answers to my questions. I am only 14 and am a girl. In buying a bike, Are there certain things I should look for? Honestly, I know nothing about this and that is why I would like to learn. I know there is certain equipment like a good helmet, boots, goggles, chest protector, and gloves that I need. Anything else just please add in your answer. THNX SO MUCH!(: