1. You will not become World Champion of Public Speaking.
— you will not even become your District champion.
2. You will not become a professional speaker, earning your living through speaking.
3. The great majority of professional speakers did not get to be professional speakers by being Toastmasters.
What does all that mean?
A. “if you believe it you can achieve it” is wrong, but “if you don’t believe it you will not achieve it” is probably right. Keep believing – while it is not sufficient, it is necessary.
B. Toastmasters does not make professional speakers. It makes more competent communicators, people able to give better feedback and better leaders. You will never get rich or famous by becoming great at 5-7 minute speeches. What a Toastmasters club can do is provide the environment for people to improve and self-help themselves and others to life changing gains in confidence and competence.
C. That is all very good. Most Toastmasters only participate inside their own club, and they enjoy becoming and building a local community/network of supportive friends.