To your first question, check out From Synagogue to Church by James Tunstead Burtchaell.
A parish is a type of administrative subdivision. It is used by some Christian churches, usually liturgical churches, and also by the civil government in a number of countries.
In the Catholic Church, each parish has one parish priest (as he is usually called in England, Ireland and Australia, among other places) or “pastor” (as he is called in the United States, among other places), who has responsibility and canonical authority over the parish (the Latin for this post is parochus).
A parish priest may have one or more fellow priests assisting him. In Catholic usage this priest is technically a “parochial vicar”, but is commonly called an “associate pastor” or “assistant pastor” (or just “associate” or “assistant”), a curate, or vicar - common as they are, these terms are inaccurate and many dioceses have recently begun using the canonical term “parochial vicar” even in general parish communications (bulletins and the like).
Each parish normally has a central church, called the parish church, where religious services take place. Some larger parishes or parishes that have been combined under one pastor may have two or more such churches, or the parish may be responsible for chapels (sometimes called “chapels of ease”) located at some distance from the parish church for the convenience of distant parishioners.
I don’t have any information on “congregation.”
As for why we call priests “Father”, check out the article: Call No Man “Father”? at the Catholic.com website.
I hope this helps.