Story/Progression Help

So basically I've did all the main scenerio until Ifrit. So I killed him.
When I tried to join a GC it tells me I should advance further into the main storyline. I've travel to LL,Grid, and Uldah, but have yet to see the storyline ICON anywhere on the map.

Quest that are red not sure if have to do them(Not main storyline)

Taking the Black( Can't do due to not being ARC lvl 15). So my question do I really need to do this one? to advance deeper?.

The quest directly after Lord of the Inferno (killing Ilfrit) is called A hero in the Making and I'm literally just on it. You get it from Minfilla in the Waking Sands.

http://ie.ign.com/wikis/final-fantas..._in_the_Making