I wish to ask, do Jews believe that Moses never called non-Jews to the worship of one God?
It's my understanding that mainstream Judaism doesn't believe this and never did. This "idea" falls under the category of "things Non-Jews think that Jews believe." One reason this idea keeps being falsely attributed to us because Judaism is a religion, culture, and ethnicity and so it's harder for other religions to conceptualize. Another reason is because Jews don't view every verse in the Bible as applying to "everyone." Jews view that most commandments are specifically commanded to the Jews and not necessarily to anyone else. In much the same way I give rules and expectations to my kids that I don't expect from other kids. But does that mean if I ever adopted a child I wouldn't treat them the same as my own children?? Or that I view other children as less holy or worthwhile than my children?? God forbid!
I use this example to explain that God has specific expectations and rules for His firstborn children the Jews, but anyone who converts also becomes a Jew and is accepted into this special relationship with God.
If Jews do believe that he did call non-Jews to one God, how did they come to the belief that one can only be Jewish through some kind of blood heritage?
Again, Jews don't believe that blood is required to be Jewish. And Jews don't believe that Moses or God excludes non Jews. These ideas fall under the category of "things non-Jews think Jews believe," and are easily disproven.
The first and biggest example to show that Moses was sent specifically to the children of Israel as their savior and redeemer BUT not excluding anyone else who wanted to join can be found in Exodus 12:37. When the Israelites are getting ready to leave Egypt we hear of the mixed multitudes who join them. These mixed multitudes are a mix of other non-Israelite people who were living in Egypt when all the plagues and miracles were happening.
37 Now the sons of Israel journeyed from Rameses to Succoth, about six
hundred thousand men on foot, aside from children. A mixed
multitude also went up with them, along with flocks and herds, a
very large number of livestock. And they baked the dough which they
had brought out of Egypt into cakes of unleavened bread. For it had no
yeast, since they were driven out of Egypt and could not delay, nor
had they prepared any provisions for themselves.
In Hebrew we call them the Erev Rav and here's a wikipedia article about it. These people are considered to have fully joined the Israelite nation after choosing Moses as their prophet and the Israelites as their people.
I'm not aware of any statements by Moses or any other later Judean/Israelite prophet in the Hebrew Bible that viewed their mission as ONLY being to the Judean/Israelite people. We've shown that Moses was inclusive in the beginning of the Bible, but even near the end of the Bible we have another example named Jonah, an Israelite prophet who was sent to save Ninveh the capital of Assyria, despite those people not believing in the Jewish faith.
But since answering your question required me to dispell some myths that other religions say about us... It's worth mentioning that the only Judeo-Christian figure that I've ever heard say that they came only for the Jews/Israelites to the exclusion of others was Rabbi Jesus the Nazarene.
21 Jesus went away from there, and withdrew into the region of Tyre
and Sidon. And a Canaanite woman from that region came out and began
to cry out, saying, “Have mercy on me, Lord, Son of David; my daughter
is severely demon-possessed.” But He did not answer her with even a
word. And His disciples came up and urged Him, saying, “Send her away,
because she keeps shouting at us!” But He answered and said, “I was
sent only to the lost sheep of the house of Israel.” But she came
and began to bow down before Him, saying, “Lord, help me!” Yet He
answered and said, “It is not good to take the children’s bread and
throw it to the dogs.” And she said, “Yes, Lord; but please help, for
even the dogs feed on the crumbs that fall from their masters’ table.”
Then Jesus said to her, “O woman, your faith is great; it shall be
done for you as you desire.” And her daughter was healed at once.