Generally speaking, at the main shrine , first ,throw a coin into the offering box for an offering to the God.
If there is a bell at a shrine, ring the bell.
It’s the etiquette to pray to god from here.
Straighten your back and bow twice in front of offering box (toward the god).
Meet your both hands
and clap twice.
Then, pray silently.
After that bow once.
Then back a step and leave there.
We have to wash our hands to purify ourselves before making a prayer.
Please look at 「how to clean your hands」
The manner of a rude person is paid no attention by the God.
Be careful! (>_<) This is just for your reference, there are different rules for Different places.