tampasteve has summarized the range of Christian views very well. I'll add this, in case it helps to make sense of the views:
Consider a person -- let's call her Alice -- who has grown up in the church, and who has loved God from her earliest memory. If we ask "When did Alice first become a Christian?", there are two reasonable answers you might give. 1) Alice started to be a Christian at the very beginning of her life, when she was loved by God and surrounded by family and church members who taught her about God. Or, 2) Alice became a Christian when she consciously decided to be a Christian. Churches that practice infant baptism are placing baptism at beginning-point #1, emphasizing the grace of God and the nurture given by one's parents and church; these churches often mark beginning-point #2 with Confirmation. Churches that practice believer's baptism are placing baptism at beginning-point #2, emphasizing the individual's own choice and commitment to God; these churches often mark beginning-point #1 with a Dedication ceremony.
If you are engaged to be married, then the baptism question is one to discuss with your fiance before you marry, since it's something spouses may disagree about. Will you baptize your children as infants, or will you wait until they choose baptism for themselves? (My husband and I had to talk about this and come to an agreement, because he's Baptist and I'm Episcopalian.)
To answer your last question: Most churches, I think, offer pre-marriage counselling to engaged couples. I highly recommend taking advantage of this counselling, even if it isn't mandatory in your church. It can offer good, practical advice on how two people with their different personalities, histories, interests, etc., can work together to make a harmonious decades-long relationship.