We can put all (of) before nouns and pronouns. Before a noun with a determiner (for example the, my, this), all and all of are both possible.
All (of) my friends like riding. She's eaten all (of) the cake.
Before a noun with no determiner, we do not use of. All children can be naughty sometimes. (NOT All of children . . .) Before a personal pronoun, we use all of.
All of them can come tomorrow. Mary sends her love to all of us. All we, all they are not possible.
We can put all after object pronouns.
I've invited them all Mary sends her love to us all. I've made you all something to eat.