Is it more so "morning" as in the "morning" of one's life, intended proverbially to signify the beginning of an epoch or process? I would appreciate an answer with sources. The sun, which determines the arrival of morning and evening in the literal sense, had not been created. Thank you
The Hebrew word "Erev" as used in Genesis 1:5, means "mixed up" in English or "confusion". This is because when things get darker, the human eye cannot properly identify forms; and reality is blurred.
The Hebrew word "Boker" means "clarity" or "break-through" (of light). This is because the coming of light will allow the human eye to once again recognize distinct forms and end all confusion.
This understanding and translation can be seen in the commentaries of Ibn Ezra, Radak, and Rav Shamshon Rafael Hirsch on Genesis 1:5.
Therefore, I simply like to translate the verse as:
There was chaos, and then there was order, one day.
If you follow the pattern of the creation account, you will see that the six days each have a starting point of "chaos" that is set right and becomes "orderly".
The seventh day, is "all light" since it had no chaos and was the culmination of the works of Creation. That's why the 7th day has no mention of "it was erev, and then it was boker" because the 7th day was perfect.
Another proof to this approach, is that Targum Onkelos (Aramaic Translation by Onkelos the Convert, lived 35CE - 120CE), translates "and it was good" throughout Gen. chapter 1, as "and it was good" in Aramaic ("Ar-ey Tav"). However, in Gen 1:31, when G-d says (at the end of Creation): "..it was very good", Onkelos translates that it was ("Takin Chadata") "a unified order".
I hope this helps.
Genesis 1:1–4 says that G-d created light on Day 1. The light was called "day" and the dark was called "night." Verse 5 follows: And there was evening and there was morning, one day.
How are we to understand this when the sun was not created until the fourth day? We know that light and darkness depend on the position of the sun. So, how is it possible to have light without a sun? The rabbis noted the problem. A Midrash answers that G-d created a "brighter and more enjoyable sun" on the first day but hid it for the righteous to enjoy in Heaven. This is not explicit in the text. Another possible solution is that this is the biblical style (Ibn Ezra). For example, Chapter 1 informs us in a broad statement that G-d created a man and woman, humankind, and chapter 2 explains it in detail, Adam and Eve. Similarly, it is possible that G-d created the sun on the first day (verse 3) and improved this light on the fourth day. This improvement would not only grant light but also support life, allowing vegetation to grow (verses 1–4). Although this view is also not explicit, arguably it is a more reasonable view.
There is one more possibility. It is possible that the Torah account is not meant to be taken literally. It is a parable (Maimonides). The Torah could have used terms such as “light,” “day,” “morning,” and “evening” as metaphors to mean there was an unidentified creation during an unspecified length of time that stopped for a new period of time to begin. Understanding the text this way, we might say that the six-days are to be understood as six periods of time. The Bible is saying that creation took place during a long process with different eras. Thus, Judaism can accept evolution and that the world is millions of years old.
 This is also a Catholic tradition
 See Babylonian Talmud, Ketubot 57b, where yamim (days) could mean years