Cho'gath support is much like other tank supports similar to Tahm Kench or Alistar. You are fairly weak and squishy until you gain a few levels and get points into some of your spells. Try your best not to die because once you get over the early hump then things get much better.

Avoid spamming your abilities too much as you can end up spending a lot of mana quickly (Q+W combo = 110 mana). Try to stick to poking with your Rupture in the early levels because it only costs 60 Mana and you can build up your Manaflow Band that way.

Your ultimate does 1000 damage to minions, enemy jungle monsters like the scuttle crab or blue buff and epic monsters like the dragon or baron. That's no joke either, you can be great at securing or even stealing these objectives (but don't get stupid).