Despite the dominance of Abrahamic and other monotheistic religions namely Islam, Judaism and Christianity several pagan and indigenous religions are still in practice today in several parts of the world. Hinduism for instance is believed to be the world's most ancient religion to have existed to date. Hindus or more precisely Vedantists are the predominant religion in India, Sri Lanka and Nepal. Besides Hinduism there is Shamanism still in practice in US which was the religion of Native Americans.
Well, It really depends on what religion you are talking about. For instance, I am Budhist and live in the U.S. In the barren dessert part known as New Mexico. There are a TON of religions here. One friend of mine is a Jehovah witness, so he doesn't celebrate holidays even his birthday. Other friends of mine are Navajo, and I'm Cherokee/Irish, so it really depends. You should look into African indigenous tribes as a point of interest