Hi SIMON55, the answers to your questions according to the Bible are yes & no respectively.
Genesis 1
27 God created man in His own image, in the image of God He created him; male and female He created them.
31 God saw all that He had made, and behold, it was very good. And there was evening and there was morning, the sixth day.
Genesis 2
18 Then the LORD God said, “It is not good for the man to be alone; I will make him a helper suitable for him.”
Cain and Abel are mentioned in Genesis 4 as
the first two sons of our progenitors, but both boys were lost to them, first righteous Abel (who had no generations/no family that continued after him), and then evil Cain, whose family line was ended forever by the waters of the Flood.
Genesis 5 concerns the "
generations of Adam", his family line
that continued on through Noah and then beyond the Flood.
Genesis 4
1 Adam knew Eve his wife, and she conceived and bore Cain, saying, “I have gotten a man with the help of the LORD.”
2 And again, she bore his brother Abel.
25 And Adam knew his wife again, and she bore a son and called his name Seth, for she said, “God has appointed for me another offspring instead of Abel, for Cain killed him.”
26 To Seth also a son was born, and he called his name Enosh. At that time people began to call upon the name of the LORD.
~Deut