Yoga was originated approx. 5000 years ago in ancient India. Yoga simply means to add, to unite or to join. In Indian philosophy, yoga is adding your soul (atma) into the God (paramatma). The ultimate goal of yoga is liberation (mukti or moksha) as everyone wants to be free from this arduous and painful life. In India, Rishikesh was the destination of all great sages who were seeking the peace.
Many sages such as Swami Sivananda, Vivekananda, Dayananda, Mahesh yogi and others got inspired in Rishikesh. So, you have chosen the right place to learn yoga; Rishikesh which is covered by the beautiful Himalayan mountains and situated on the banks of holy river Ganges/Ganga.