I was lucky enough to find myself absorbed into hubby's friends as if I had always been one of their own. At first I let it bother me that I didn't have friends of 'my own' because I have always made friends easily. One day it dawned on me they were, and still are, my own friends.
Still, groups of like minded people, through hobby clubs, book clubs, sports etc are a great way of meeting people. Work can lead to friends too.