The points on eNotes aren't directly useful for anything. They are simply an indication of how a person uses the website. If you have friends also using eNotes, points can be used to compare how often you use it in comparison to the others.
You earn points every time you ask a question on eNotes. You earn points every time you post a reply to a discussion on eNotes. You earn notes if you can post an answer to a question asked by someone else on eNotes.
As you use the website more often, you may start looking at the number of points accumulated by various editors. The more points an editor has for a specific subject area, the more often that editor has answered questions in that area - which might mean s/he is more knowledgeable in the area.