*most* women need clitoral stimulation to reach orgasm.

For the g-spot - imagine you laying flat on your back.
He inserts his fingers into you with his palm facing the ceiling.
If he then gently curls his fingertips up slightly and pushes gently up and forward - towards your belly button - that is where the g-spot is located.

But if you can orgasm happily with clitoral stimulation then you are doing just fine.

If one day you happen to orgasm without clit stim - then bonus, other wise don't worry about it.

Clit orgasms are generally deeper and harder too.