You gain levels in the soul magic skill line as you complete the main story quests. No way to speed this up except by completing the quests quickly.
The undaunted skill line increases as you complete group dungeon achievements, but you also get points towards it when completing the normal and veteran pledges (the normal pledges become available when you reach lvl45, and the veteran pledges become available when you reach VR1).
I would recommend killing every boss in both the normal and veteran dungeons, as well as the quests in those dungeons. After that, check the achievements section of your journal to see what group dungeon achievements you have not acquired. Some achievements, like the speed runs, can be difficult to obtain without an experienced group.
Any points that you're missing from difficult achievements can be made up by doing the pledges every day.
Will reading the books work for the undaunted?