how to diconect my family from icloud

i was the first to have iphne, apple id, and icloud.

it happened that all the family uses my apple id and my icloud.

my sun uses my old iphone, thoght he erased everything and started from the beginig to download his iphone, when we are at home on the same time, our phones behave like one, i get his phone calls and he gets mine...

i have created a new apple id, and password...but it has only massed it all.

how can i disconect?