Did Adam have a navel since he was created not born? Did Adam have any sex organs before Eve? Did the animals also live forever before the sin, and, if so, why do they die since they have not sinned?
The Bible says very little about your first two questions. The Bible is primarily a book about relationships between God and mankind. In it we learn how God loves us and how He wants us to love Him in return. Through its pages we see how others strove to do this and we are encouraged to do the same. The Bible, as the Word of God, gives us instructions on how to live (Matthew 4:4) and does not include every scientific or historical detail.
Perhaps the best passage we can turn to in connection with these questions is Genesis 1:27. Here we read, "So God created man in His own image; in the image of God He created him; male and female He created them." This passage indicates that mankind was created male and female, but says nothing about whether Adam had a navel.
In Genesis 2:7 we note that when God created Adam, Adam became a nephesh—living being. The same Hebrew word is also used to describe animals in Genesis 1:20. While both humans and animals are living creatures, made of flesh and therefore subject to death from the start, the Bible says that man was created to rule over "all things" including the animals (Psalm 8:4-8; Hebrews 2:6-8). Furthermore, mankind has been offered the opportunity to become sons of God (John 1:12; 1 John 3:1-3)—something not offered to animals.
In addition to the fact that mankind was designed in the image of God (Genesis 1:26-27) with the potential to become sons of God, the Bible also reveals that at the time of death, the spirit of man goes up to God while the spirit of animals goes down to the earth (Ecclesiastes 3:21). Animals are a wonderful part of God's creation and should be treated with respect, but they do not have the same potential as human beings.