The grind so far has been so tiring that I'm not trying out new classes. It'd be so freaking painful to go through same stuff, after all.
Level 30? Wow, that's fucking awful...Well, I just checked dungeons from wiki. At the very least, you can start from lvl 30 and upwards for that.
Group finder prior to that is probably for "Group Event" quests that you need to be together with other people to kill spawned field Bosses, but the server I'm playing is crowded enough that I never need a group finder mechanism to do the quest together with, I'd say.