You need to be around level 15 before you start the first group dungeon

i think it becomes available at 10. im level 12 and there are three dungens available for me to run.

You can definitely do the first tier of group dungeons at level 12 (maybe even as low as 10), but you'll have a much easier time if you wait until level 15, because that's when you unlock weapon swapping, and in group dungeons it's hugely useful to have 2 skill bars worth of skills to choose from in boss fights.