How to get them to get along

maddy • 3 miscarriages 1 born (6months ) and 1 on the way !

Help !! I just got a new cat it was a stray and I want my cats to get along the boy (the first cat I had) doesn’t like the new cat (who is a girl) he grows and hisses at even smelling her on our clothes . They r in deprecate rooms for now and idk how to introduce them to each other

This is stark the cat I had first

This is our new cat idk what her name is yet