Archetypes are instinctual and universal reactions to stimuli that is the same across culture and across time. Carl Jung explains that archetypes are a part of the collective subconscious of man. In expanding on the first answer, i will address each of your individual items:
Goodman Brown: The name suggests that Young Goodman Brown could represent any person entering adulthood who attempts to live his life according to the prevailing moral beliefs and codes. The surname is a common one, implying this universality. However, the first name, Goodman, also implies a type of naivete on his part. As he learns, he is not the first member of his family to enter the forest.
Faith: Faith as a person does represent faith as a concept. Beyond that, faith is everyman's "solid rock" so to speak, something to believe in and someone who will always belief in him.
The Forest: Archetypally, the forest is a place filled with darkness, chaos, sin, and evil. Its darkness provides a cover for evildoers, and it houses wild and untamed creatures. Ironically, Goodman enters this evil to prove that he can overcome it. The reader comes to see that he cannot overcome sin and the devil on his own, particularly if his ancestors and town clergy have been unable to do so.
Night: Much like the forest, night is also dark, implying that people can hide their sins under this "cloak of darkness" and participate in activities they would never dream of doing in the open light of day. It is the time of the devil and goblins.
The Journey: Everybody is tested. Everybody wonders if he or she can stand up to the test, particularly the test of good versus evil. People succeed in proceeding down this path to varying degrees. Very few, if anyone, succeeds without harm. As we see, the price of Goodman's journey was his loss of Faith, both literally and figuratively.
An allegory uses symbolism to represent human characteristics and situations. Goodman Brown's name refers to Everyman, and his wife's name, Faith, represents his own faith in God and in humanity. The dark woods come to represent Goodman's own hell because he's torn between his faith and giving in to evil, the struggle which every man must confront. Goodman tries to resist the temptation of the devil, but he continues his way into the darkness of the forest, unsure of what to do. In the end, he takes his own personal hell with him because he distrusts his wife and the other people for the remainder of his life. This alienates him and deprives him of the life he could have had.