No. Just no. FFXIV is a very easy MMO with classes that have been so homogenized that if you can't figure out how to play a class within a couple minutes at max level, I don't know what to tell you.

If you want to learn to tank, start one of the original tanks and level up until you get to the level of a newer one. Same goes for DPS or heals. They all play nearly identical with a little bit of different flavor on each. Not enough to warrant the incredibly slow and dull grind of leveling them all the way up just because.