If you don't mind a bit of reading, I'd like to suggest Kassandra's thread The Ancestor Altar
. This is the part that gave me the feels:
Hoodoo takes into account that everybody's family situation isn't the same, nor ideal. Some people don't even know who their blood relatives are. Some don't feel "connected" to their family of origin. Some are adopted by non-bloodline people. In hoodoo, there is allowance for all this. A practitioner could simply "adopt" any "new" ancestors to whom they feel a truly strong connection. Adopted ancestors are just as important as bloodline ones are, and all of the above about bloodline ancestors would likewise apply.
Hoodoo, as far as I know, isn't a closed spiritual practice, so you could incorporate ancestral adoption into you own practices if you wish.
My personal belief is that if you don't want anything to do with your living family, you don't need to. I've got all kinds of living relatives, but very few made much of an effort to have any contact with me during these 29 years that I've been alive. Aunts, uncles, even half siblings, you name it, I've been ignored by them. My grandmother lived half a block away from me for years and not once did she reach out to me. Does it bother me? Not at all. You can't miss the people you don't know.