Don't forget to pull out your Chocobo, once you unlock it, and use it for every single fight you can. It will still probably take you 3 class/job leveling to 50 before you max it out but at least it won't feel so much like straight up grinding. You can thank me later.
One last point. When you spend SP on skills on your chocobo remember that you can only unlock the Relic barding if you spend all your points in one skill tree. Each tree has a unique barding. IMO attacker owns them all as you get a Dragoon style barding.
If all you do is dungeons then ignore this post since you won't ever use your chocobo in combat. I have a friend that does that.