As Christians, our starting point is that Scripture is always true and truthful.  (Numbers 23:19; John 17:17)  That means that if Scripture says one thing and other sources say something else, we side with Scripture.  We side with Scripture because God is ultimately its author, even though he used human beings to write down his words.

Another important principle regarding Scripture is that we interpret Scripture as the context directs us.  This means understanding the genre of the section of Scripture under consideration.  Genesis 1 and 2 are historical narratives.  So, we understand the content literally, not figuratively or poetically.  Thus, the “days” of Genesis 1 are days—periods of time that have “evening” and morning.”  There is nothing in the language of the Bible’s creation account to indicate that the days were longer than 24-hour periods.

References to 2 Peter 3:8 (“With the Lord a day is like a thousand years, and a thousand years are like a day.”) have no connection whatsoever with the creation account.  2 Peter 3:8 speaks of God not being bound to or affected by time.  A day on earth affects God no more than a thousand years on earth.  God does not age.  He is not affected by time.  He exists outside time.  He is eternal.  When people try to say the days of the creation account were longer than 24-hour periods because of what 2 Peter 3:8 says, they are guilty of illegitimate biblical interpretation.

Do we find variety within species?  (That is another question you raised.)  We do.  But we do not find change going across the biblical “kind” (Genesis 1).

Carbon dating is not as precise as it is made out to be. There are numerous papers on file at Wisconsin Lutheran Seminary that address creation and evolution.  You will find some of those papers addressing the fact that God made the world with the appearance of age.  (There were fully mature fruit trees, for example, to provide food for Adam and Eve.)

I can also direct you to the website of the Lutheran Science Institute, an organization within WELS, that can provide you with even more reading material.

When it comes to creation, the Bible presents an eye-witness account.  The only one present was God, the Creator.  He tells us that he spoke and called things into existence.  He did not oversee an evolutionary process, nor were things made apart from him.  He spoke, and his powerful word created.  “In six days the Lord made the heavens and the earth, the sea, and all that is in them” (Exodus 20:11).  The biblical record is clear:  God is the creator.  God bless your study of his word.