Looking for a start

I am a 29 year old business owner residing in the Sth West of Melbourne. I have no experience in acting or theatre outside of the odd play I did in High School. I am not very good at singing or dancing, however, I am the envy of my friends and colleagues in that I love to speak in public. I am a 6 foot 6 man with a dominant public presence. I feel more comfortable in front of people than anywhere where else.... It is about the only time a sense of calm comes over me. I work in a very stressful work environment and I am looking for a hobby and would really like to try some acting? Does anyone have any advice on where or how I should start?