I am a yoga instructor. Have you ever tried it. It is  a group of physical, mental, and spiritual practices or disciplines
No I have never tried yoga but I want to learn it, I heard it is fun
Oh yes it is fun and there are some many places to learn it. We have so many schools for practices and goals in Hinduism, Buddhism, and Jainism.
oh nice, do you meditate while doing it?
Of course yes, because it is of both physical mental and spiritual discipline 
How long does it take you to learn a perfect yoga?
Well I cannot give you a direct answer on that because  yoga-practices is unclear, varyingly credited to Hindu Upanishads.