The priest, of course, the god parents, the parents, the baby getting baptised, other family and that's about it unless you're do it during a regular mass then you have all people in the church.
the baptism takes place in a church
No, Buddhism did not teach baptism before Jesus. It is not part of that religion.
No. A baptism is the rite of becoming part of the church by the dipping in or the sprinkling of water. A message is a communication.
Baptism
the baptismal font
Not every church have a second part to a baptism, but in the The Church of Jesus Christ of Latter Day Saints a person is confirmed a member of the church.
For Christians it's called: Baptism
Christians take part in baptism and confirmation because it's a part of their religions practices. In their holy book, the Bible, many people read the translation and see that these are commandments from their God they must follow.
It symbolises purification, cleansing, and as baptism is considered cleansing of 'original sin', its a powerful symbol for us to use.
it is a time when a baby is becoming a part of family with god
Baptism, Communion.
This is a fairly short answer to a very complicated question. First, let's assume we are talking about water baptism. Some Christians talk about spirit baptism. That is a whole other complicated issue. Three main views on water baptism would include: 1. Water Baptism is part of regeneration. That is, baptism is part of the salvation experience. Without this ritual, one cannot be with God. 2. Water Baptism is a purveyor of grace. Baptism may not save or be part of the salvation experience in the strictest sense, but God gives sacramental grace for the action. 3. Water Baptism is an act of identification. When one decides to follow Christ one publically carries out baptism as a way of identifying with Christ and the church. The first two of these would focus on baptism as a spiritual ritual. The third would focus on baptism as a symbolic ritual. The early church practiced two main rituals. These were Baptism and Eucharist (or Lord's Supper). Some Christian groups have added more over the centuries. There may be other views (especially as one broadens one's definition of Christian), but this is a start.