Red Mage main here.

Right now I would say the answer to your question comes down to whether or not you want to play a Caster class. Red Mage is an excellent first Caster in raids to play--you can very intuitively learn and master slidecasting because you can practice sliding with vercure anywhere. Slidecasting is a universal art, you get the hang of it on one job you've got the hang of it for all jobs, and you might even learn to be cheeky with aoes in the same way.

That said: casting is not for everyone and learning to cast is one of the hardest things in a game like XIV that has as much aoe spam as it does. You find a lot of variance in caster damage on the leaderboards borne of many factors, but a major one being a low cpm born of not finishing casts. There's a bit of daring you'd need to learn and get used to with any caster, and if that doesn't sound appealing then a melee or a ranged would be a much better pick.

Also worth considering is, if you choose Red Mage, you'll probably get asked "can you roll Summoner instead?" more than once. After hearing it enough, even from good natured people, it can wear on you a bit. Be aware that the question will exist with the current RDM v SMN balance.