I see you can upgrade your gear with some of the Shadowmoon quests to increase your armor a bit. Furthermore you need 415 defense (with Survival of the Fittest) to be immune to crits from bosses/mobs, which is essential for any tank. You need around 20k armor with your current hp since armor is your main damage reducing trait. You could also use to upgrade your dodge a little.
There is a head enchant at caverns of time - revered. This one is a must for a druid tank, and you could use to enchant your gear in general, but I understand if you wanna wait til you got at least blues before you do that.
NOW for the main point. You're undergeared! We need kara ready people to raid with cause we've had too many bossts going on lately, and the boosted ones left the guild after they geared up. Prove you want to raid. Get 20k armor, 14k hp, 20% dodge and report back (thosee stats are not exact, but aim for it)