I want to create a simple User Activity Log. What fields would I need in the table, I assume I would need a new layout (would a list, table or report be best for this). Also how would I do the Opening Script for the file.
What user activities do you want to log in the Activity Log?
You'll want a table for this. A layout for that table will be created automatically when you add the new table. You'll need fields in that table to record the type of data you want to record in order to "log user activity"--whatever that turns out to be in your context.