People who follow Jainism, an ancient Hindu religion, are called Jains. They mainly live in India. It is a spiritual religion. As you have asked many questions in one go. Point wise reply to your queries is here as under:
1. Teachings of Jainism: there are 4 teaching of Jainism. These includes : Ahinsa or non violence, satay or truthfulness, brahmcharya and asteya or non stealing. According to these teaching anybody should not cause harm to any living beings, speak truth only, not to steal anything and not to involve in sensual desires.
There are Triratna of Jainism or three principles of Jainism. These are: Right faith, right knowledge and right conduct.
2. In India, mostly Jains community lives in Rajasthan, Maharashtra and Gujarat. However, they are scattered across India.
3. In India only 4,451,753 Jains population is there (Census 2011).
4. There are many pilgrim place or worship places present throughout India. Most famous temples are Dilwara temple located in Mount Abu, Rajastha; Gometeshwar Temple, Vindhyagiri hill, Karnataka, Sri Digambar Jain Lal Mandir, New Delhi; Ranakpur Jain Temple, Ranakpur, Rajasthan; Ahimsa Sthal, New Delhi; Palitana Temples, Bhavnagar, Gujarat; Sonagiri Temple, Datia, Madhya Pradesh; Shikharji Jain Temple, Parasnath Hill, Jharkhand; Kulpakji Temple, Telangana; Hanumantal Bad a Jain Mandir, Jabalpur, Madhya Pradesh; Parshavnath Temple, sandstonet, Madhya Pradesh; Dharmanath Temple, kochi, Kerala; Saamvira, kambada Basadi, Moodabidri, Karnataka, Naya Jain Mandir, New Delhi; Ellora Caves, Ellora, Maharashtra; Parshavnath Temple, Varanasi, UP; Shatrunjaya, Gujarat etc.
5. Oldest Jain Temple is Shri Digambar Jain Lal Mandir, Chandni Chawk established in 1956.
6. 'Agam' scriptures are considered as sacred/ holy book of Jains.These were compiled by Indrabhuti Gautam Swami, chief disciple of Lord Mahavira.It comprises of 12 Angas(parts).