I am extremely reluctant to do your homework for you, and you are asking too many questions at once to handle in a single response, so I'll try to tackle part of the education you appear to need.
JavaScript is an object oriented scripting language, as such, there are a number of Object()s that you can instantiate, and as it works out, there are a number of ways to instantiate those Object()s. You could create a new Object() and store it in a variable, or you could imply that you want to store a new object in a variable a = {}.
Objects in turn can store either functions, values or additional Object()s as named members. If you have an object a, you can access a member function or Object() with the syntax a.member. That accessor is available both for read and write operations on that member. The accessor, when referring to a static value or Object is sometimes referred to as a 'key'.
Hopefully that helps a bit, good luck