Many people believe our conscious souls are immortal and we will be fully aware of our experiences after death.
My question is, "Did our immortal soul experience an eternity of existence before our births?"
This is a really deep question. I have no hard facts or references to back up what I am about to say, but I tend to believe that our souls are born with our bodies but can continue on after our bodies die. The beginning of my soul isn't a cornerstone of my personal beliefs, and I am open to discussion about it... its just what I think.
I think this is a question that everyone needs to determine this for him or her self. Some people feel strongly about this, whereas others spend their whole lives unsure. I suggest talking to your family members and loved ones, religious leaders and so on. Read what others think and then decide what you think for yourself.
Yes, different religions believe different things. If you are interested in learning about those religions that do believe that we existed before our birth, you should check out lds.org. More specifically, the following link will take you to a story about Abraham talking to God about the creation of the earth and that we were all there when God planned to create the earth. One verse is only the beginning, though to a wide-range of study. But hopefully this is a good starting point to your research.
That depends on what you believe, of course. There are religions that believe that this is what happened. I personally don't think that it is true. I think that our souls are created along with us when we become physical beings. But of course there's no way to know in this life.