Well, you're "supposed" to wait until like 13-14, but most people get one at the age of about 8? (: Hope this helps...whether you're wondering or your parents are.
I tried to get on facebook but I would be sent to my sister's account (who had been visiting until today). How do I get Facebook to direct me to my account, not my sister's? It's our computer.
Type 'Facebook' into your browser, (Google), click 'Facebook', then click 'sign up' or 'create an account'...(I forget which it says...) Then enter your information and set up your page. Have fun...(: