Was an entire race of men and women created on day 6 of Genesis 1? Is the creation of Adam and Eve in the garden a separate account at another time in Genesis 2?
Matt, thank you for your good question. It seems to be an increasingly common one these days. Fortunately, I think it is one for which there is a fairly straightforward Bible answer: Adam and Eve were the very first man and woman and all humans have descended from them. And, the creation account of Genesis 2 is simply a continuation of and elaboration on Genesis 1.
But first, why does the question come up? There are aspects of the Genesis text which seem, to allow for an interpretation like the one you ask about. For example, it is argued that in Genesis 1:26 the Hebrew word adam is the general term for man and should be translated “mankind.” The NIV translates it this way while the KJV and others retain the translation “man,” a translation that is not incorrect but perhaps less precise. It is maintained that this is a plain statement that God created the entire human race on Day 6. Next, it is suggested either that Adam and Eve are fictitious characters chosen by God to tell the story of sin and its consequences, a position held by the likes of Alistair McGrath and C.S. Lewis, or that they were actual historical people who were chosen as representatives to the tell the story, a view promoted by Billy Graham and Tim Keller. Both of these explanations are given to account for a so-called second creation story found in Genesis 2. Another argument made in favor of this view is raised from Genesis 4:13-17. Why it is asked, does Cain express fear for how he will be treated by others as a fugitive and wanderer on the earth? And, why does God put a mark on him to protect him from others? Additionally, who lived in Nod and how does one account for Cain’s wife? Finally, it is argued that the number of people on earth at the time of the flood couldn’t possibly have descended from a single man and woman in the time permitted by the text—ten generations (Genesis 6:1ff).
Obviously, there are some substantive, textual concerns here which need to be addressed (and are in other places). It should be pointed out, though, that there are other, very simple texts that comment directly on your question. So, let’s take a look at those.
First, Paul plainly affirms that Adam was the first man. He says:
Thus it is written, “The first man Adam became a living being”; the last Adam became a life-giving spirit. But it is not the spiritual that is first but the natural, and then the spiritual. The first man was from the earth, a man of dust; the second man is from heaven. As was the man of dust, so also are those who are of the dust, and as is the man of heaven, so also are those who are of heaven. Just as we have borne the image of the man of dust, we shall also bear the image of the man of heaven. (1 Corinthians 15:45-49, ESV)
In this passage, Paul quotes the latter part of Genesis 2:7 and claims that Adam, who became a living being according to that passage, was the first man.
Second, Eve’s name means “the mother of all living.” Genesis 3:20 says, “The man called his wife’s name Eve because she was the mother of all living” (ESV). Clearly, as Paul calls Adam the first man, so this text indicates that Eve was the first woman. This text additionally makes the point that all subsequent humans, including us, descended from Eve and Adam.
What does this mean for the creation account in Genesis 2? It simply means that after telling us generally what He did on Day 6—created the human race through the creation of the first man and woman—God then gives us a closer look at the creation of Adam and Eve. Is Genesis 2 an account of a later creation? No. Jesus said,
Have you not read that he who created them from the beginning made them male and female, and said, ‘Therefore a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh’? So they are no longer two but one flesh. What therefore God has joined together, let not man separate (Matthew 19:4-6)
In this text, Jesus combines the creation of male and female recorded in Genesis 1 with the institution of marriage recorded in Genesis 2. We can, thus, conclude that they are meant by God to comprise one creation account—the account of the creation of the first man and woman, Adam and Eve.
The Apologia Institute
 The Hebrew word for man (adam) is the generic term for mankind and becomes the proper name Adam https://www.biblegateway.com/passage/?search=Genesis+1&version=ESV