Hinduism is not like any other Religion.
It has no founder nor basic tenets. so it is the most free
Religion on earth.
There are no fundamental Hindus because there are no fundamental
principles to believe.
You can live as non-believer also in Hindu Religion. It is not a
sin.
People practise religion in many ways.
PRARTHANA ( Prayer ) ARAADHANA ( Worship) JAPA ( Chanting)
DHYANA ( Meditation) ADHYANA ( Learn /Read holy texts) area few
Practices.
Japa ( Chanting/reciting holy names of Almighty - like hare
Krishna) Dhyana ( Meditating - hundreds of ways to do this right
from remembering the Sacred Syllable AUM ..viewing the light/lit
lamp, view bruhmadhyam ( centre of forehead), focusing on
ISHTADEVTA ( favourite Idol) Image, Kundalini Dhyana, Rajayoga
dhyana, TM, an so on so forth) Living observing YAMA / NIYAMAS are
also worshipping, Go to Temple and holy places and worship, Do
achaaras, ADHYAYANA ( Learn) is another way. some people observe
VRATAs (Fasting) others follow strictly YOGA & PRANAYAMA
Practises. There are thousand practices to follow. There are no
established hierarchical control like church in Hindu society. So
you are a free bird to find your path.