In answer to your question, “Is there a pre-Adam?” The answer is no.
Adam was the first man created by God.
Gen. 1:26, And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth. 27So God created man in his own image, in the image of God created he him; male and female created he them.
Gen 2:18, And the LORD God said, It is not good that the man should be alone; I will make him an help meet for him. 19And out of the ground the LORD God formed every beast of the field, and every fowl of the air; and brought them unto Adam to see what he would call them: and whatsoever Adam called every living creature, that was the name thereof. 20And Adam gave names to all cattle, and to the fowl of the air, and to every beast of the field; but for Adam there was not found an help meet for him. 1 Cor 15:45, And so it is written, The first man Adam was made a living soul; the last Adam was made a quickening spirit. 46Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual. 47The first man is of the earth, earthy: the second man is the Lord from heaven.
Adam was a type of Christ in that the sin he committed brought physical death to all men. Christ through his death, burial and resurrection will bring all the dead back to life at the resurrection.
Here is a list of some study books that would help you to understand the bible.
1 You should have a modern version of the bible to study along with the King James Version. I would recommend the NASV 95 update or the New King James Version.
2. A Bible Dictionary such as Smiths.
3, A Bible Concordance that will help you find scriptures by subjects.
4. A Bible Atlas is also helpful.
One should be very cautious about studying commentaries, and understand they are only mens opinions.
Never accept a commentary over plain passages of scripture.