I am a yoga instructor and know a lot about yoga! It is more than just exercise, it is also a meditative and spiritual process 
Cool. I've always wanted to learn about yoga. Just never got the chance.
Yeah, I understand, a lot of my clients have previous said the same thing, but after taking a couple lessons, they felt a lot better. 
would it help with neck and back pain?
Yes it can! Yoga is basically a lot of stretching and holding poses. It is also a popular system of physical exercise across the western world. 
That sounds really nice and I like the idea of mediating as well. How many forms of yoga are there?
There are a variety of forms. The most common type of yoga is Hatha yoga and Rāja yoga
What is the difference between those two yogas. I once watched a show where they did beer yoga. Thought that might be perfect for a night out with friends.