Morals do come from many places, for each of us, and for all of us. There are some universal ethical or moral principles that exist in every society for the simple reason that, without them, society just would not work. How could a society work if murder was encouraged, or lying, or not keeping one's word.
There also seems to be a universal repugnance for incest, and it appears biological, though the definition of what exactly is incest varies from culture to culture.
Beyond that, morals develop in societies generation after generation. Sometimes, they change over time but people don't know that. For example, in Old Testament times, a man could have two wives, as Abraham did. And the law said that punishment was "an eye for an eye" and a life for a life. Well, those changed. Monogamy is now considered correct in Judaism and Christianity, and punishments are much more lenient than then.
And this happens in societies, as well. Less than 200 years ago, debtors went to prison. Not long before that, thieves might have their hands cut off, and stealing something worth just a few dollars was a major crime.
When we see the diversity of moral ideas, we learn to be open-minded. When we think about what really makes families, economies, and societies work, we contribute to the morals of our generation. And when we develop the clarity and discipline to live a life dedicated to the good - living morally and going beyond that, to living charitably, we heal the world.