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.