JIRA has two main views that you'll use day to day, the Backlog and the Board.
The Backlog view includes the sprint backlogs as well as the product backlog, defined by tasks that are applied to a sprint and ones that are not.
The Board shows the items in the current sprint inline with their status.
The backlog will show the current sprint at the top, followed by the next sprint and so on and at the bottom is the product backlog, tasks that have not been allocated a sprint.
Filtering by the epic and the platform, will show you the stories and tasks that deliver that epic for that platform.
In this example below, the epic is to deliver HD as a premium user feature. There is a story (TII-81) which has one point for testing and QA, then two technical tasks that deliver that story, TII-211 and TII-437 with two points each. The epic therefore has a total point value of five points.
The board shows all tasks that are in the current sprint with their status. Tasks move from the left to the right, the more tasks on the right, the happier everyone is.
Using the quick filter "Only My Issues" will filter out all issues apart from the ones that have been allocated to you. During the sprint, this is the view you should be using.