Monalysa

I am really interested in beginning ballet within the next few months. I am a very determined person, so I will work hard to be good. I have a history of tumbling and cheerleading and I am 16. I am super flexible and strong. So I was just wondering if anyone could please tell me about how long would it take to start pointe? What should I be practicing prior to beginning pointe? Are there any tips? Thanks! Any advice is helpful. -Monalysa