Ya'll not seeing he's not technically a blm yet and none of that stat stuff really matters til he's at /least/ 50+.

THM is a slow class to get into. Once you get 30 and are a proper BLM, it picks up some. The main meat of the class is to balance not just fire and ice, but also upkeep on thunder (so thunder is a BIG DEAL even at low levels. It doesn't seem like a lot now, but damage over time adds up!). It's a glass canon at higher levels, but right now you're a squishy mage.

If you're not enjoying the class, however, once MSQ allows you to go to different cities freely, you can always try a different class. If you want something that hits fast and hard, there's Pugilist -> Monk. If you prefer casters, at the moment you have THM/BLM, and ACN/SMN from Limsa. Once you get higher up, you can also unlock Red Mage.

Also before I get fire under my ass, updating your gear IS important, even for low levels, but grabbing HQ or "top of the level tier" gear is worthless. If you have Road to 70 buff, you'll out level it way too quickly. Pick up upgrades where you can, but don't stress it.