Level 12? I suggest just going to La'Theine/Konschtat/Tahrongi and Leveling there until you're ~15 or so and can safely solo in Valkurm/Buburimbu.

I haven't checked FoV Zones lately, or GoV zones... try here: http://wiki.ffxiclopedia.org/wiki/Field_Manual Look for mobs around 10~12 to exp on, and you can try doing a page.

You can also turn on your Party flag and hope for an invite to Valkurm Dunes.

Either way, Soloing on BLM can be pretty easy if you let it, I suggest trying to learn Solo guides too like this http://wiki.ffxiclopedia.org/wiki/Black_Mage_Solo_Guide

Also, Try looking up mobs of the "Worm" Family, You can DoT and nuke them safely, even ones as high as VT~ with time. Just takes time/practice and a little familiarity with mobs that might be "too high".