I'm a qualified Yoga instructor. The training doesn't have to take a long time - you either do 200 or 500 hours but these can be done over as long as two years (just at weekends) or as quickly as one month (every day, intensive). Mine was 500 hours and I did it in India... on the beach 
People wil probably tell you how competitive all these areas are, but everything is competitive these days! I think it comes down to passion - if you really love something, you'll have the energy to make yourself succeed. If you get into something half-heartedly it doesn't tend to go as smoothly.
Take your time before you make a decision. And remember that whatever choice you make, you can change your mind! We're very fortunate these days that changing career isn't uncommon. A lot of my friends have done it. After working in jobs they hated for their twenties they got to a point where they realised it wasn't worth it. It's better to be fulfilled than to be wealthy imo. [/tangent]
“I'm glad mushrooms are against the law, because I took them one time, and you know what happened to me? I laid in a field of green grass for four hours going, "My God! I love everything." Yeah, now if that isn't a hazard to our country..."
― Bill Hicks
"Sometimes eating the wrong food with the right attitude is a better choice than eating the right food with the wrong attitude... That’s how powerful the mind and the heart can be in the healing process."
- Chris Kresser