I need some advice on offering a health coaching service

Fellow warriors and life entrepreneurs,

I graduated college last year as a computer science major. However, I lost interest in that field and started getting more and more interested in and passionate about health and raw nutrition, especially raw foods and the raw food diet. Over the last year, I've been extensively reading about and studying the subject of raw foods nutrition. I've also taken an online certification course by one of the leaders of the raw food movement and at this point, I feel like I have so much knowledge and experience in this field that I can offer a tremendous amount of value and help people transform their health, diet and lifestyle habits and solve many of their problems and educate them about nutrition. So I recently decided that a good way to do that would be to offer my services as a raw food coach. However, I honestly don't know where exactly to start and I don't have much money to spend on marketing and advertising. I'm very passionate about this that I'm willing to go as far as offering my service for free for the first 10 clients or so just to establish a reputation for myself. I'm also willing to offer it both offline and online, although I don't have any expertise with building a website and the technical aspect of it. That's why I thought I would seek some advice here. To me it seems that a first step would be to put a website together and start offering advice on discussion forums with a link to my coaching service but I feel that would be a bit slow and that there's a better way to go about it so I thought I would ask here.

Thanks for reading,

Alex