Most of the Indians do not know the origin of the word Hindus and the Hinduism.
Present Hindus are not ready to accept the truth; they are feeling offended if some one tells the truth and choose to remain in the dark.
However I am giving the historical evidence for your information, I hope it may enlighten some people to come out from darkness to light.
Origin of Hindus and Hinduism:
The word Hindu used by Persians first after they invaded Indus valley just to identify the natives of Indus valley irrespective of their religion, then the word Hindus used by Moguls to identify natives of Hindustan irrespective their religion who are non Muslims. Then when British governed India they made a common term for Hindus to Hinduism combining various Indian originated religions and philosophies to identify people other than Muslim, Christian and Jews in India.
Hence Hinduism is not one religion but it is a common title given for many Indian originated religions like Vedic religion, Jainism, Buddhism, shaivism, Vaishnavism and many more less recognized religions of India.
Before British rule in India there was no word as Hinduism or any religion called Hinduism.
That is why you don’t find any origin to Hinduism or any founder or any specific scripture of its own.
If you look into individual religion they contradict each other and even they fought wars for their faiths.
Vedic religion was the oldest religion India in which Brahmins was performing the most important ritual of animal sacrifice and they were non-vegetarians. After 500 BC Buddhism grown stronger in India, kings got converted into Buddhism and the Buddhist king’s imposed ahimsa doctrine in the country. Brahmins could not continue with Vedic religion practices of sacrifices by slaughtering of animals against Buddhist kings, then Brahmins surrendered to Buddhist kings and they introduced new religions called Shaivism, Vaishnavism in which pujas replaced by sacrifices. Shaivism, Vaishnavism have its own individual philosophies and doctrines and books these religions actually contradicting and degrading each other e, even wars took place between them.
After a period of time they could not afford to fight against each other as their very survival was effected since their followers were confused and could not continue with any God and in any faith. The leaders of Shaivism, Vaishnavism religions compromised with each other developed new concept with new doctrines and introducing concept of avatars combining all the Indian origin religions including Jainism and Buddhism giving importance to god of each religion.
Because of this new concept of avatars; religious gurus / leader started to add any number of gods and avatars and continued to misguide the people/followers by imposing so many new customs / traditions / rituals to keep people/followers busy and away from the real knowledge of GOD. Subsequently the number of gods goes on increasing and now there are more than 3 corers of gods in India as gods.
Know About Each Religion:
Vedic religion ( Sanathan Dharm) the oldest Indian religion: God as a spirit and formless and no idol worship and only sacrifice is for the remission of sin to attain moksha. No idol worship.
Jainism and Buddhism: does not believe in god but accept the philosophy of reincarnation. Attain nirvana only by doing good works and ahimsa. No idol worship.
Vaishnavism & Shaivism : believes in God and accept reincarnation and also accept idol worship and avatars.
Hinduism: accepts all the Indian origin religions and all gods all avatars and all Idol worship etc.
Hinduism is not one religion but it is mixture of religions hence you will have to decide first what your faith is and then practice it.