Note- about the achievements, completing any category, plus completing the daily itself (any 5 categories of 9) gets you a nice big chunk of XP on that character. So it's quite a good thing you see them up there at level 1!
Definitely do not focus on "filling up a heart and moving to the next one." Everything gets you XP- vistas, skill challenges, Points of Interest, gathering, just exploring and unlocking waypoints and area names. If you find yourself getting bored with something, just move on- all your progress in that heart is saved. Oftentimes you'll find an event will take you into the zone of a heart and fill it in for you.
Explore! Lots of what makes the game crate is beneath the surface. If you look at something and think, "I wonder if I can get there," not only is the answer very frequently yes, but you'll find plenty of hidden stuff that way too.
If you're interested in joining the guild, let me know! It's always fun to get a party together to run about the world leveling. Because of downscaling there's a huge variety of options as to where you can go as a party.