Right now, dont worry about it. Just play the game.

To explain. The devs regularly update the game with more new content, these are released via patches. When a new patch comes out, the game downloads it automatically(you dont have a choice) and is therefore everyone playing with the current patch(4.57 as of this typing). Each major patch (x.1, x.2, x.3, etc) has also included an extension of the main storyline - anywhere from 5-20 new quests. So sometimes people will refer to content via the patch it was added(2.1 added the thornmarch trial along with some optional dungeons), and we sometimes refer to parts of the story as either being base or patchline(you are in the 2.0 base quests still from the sound of it, the stretch that takes you from the end of the base game up to the first expansion is the 2.x patchline). But really, all you have to do is keep following the story and it will take you through all the mandatory parts.

Once you get caught up to the current content, patch day/week is the exciting time when new stuff shows up to do. New dungeons to clear, new trials to overcome, new raids to master, new quests to complete, and the next chapter in the story to unfold.