Unfortunately, you can't really pin the gameplay to a set level range. Mostly because it varies heavily depending on what you're playing. You can get a general idea of how some of the jobs (and I specify jobs because the base classes really only teach you the basic 1-2-3 rotation - though I think that helps a lot with PUG's many moves) as you level them, such as weaving your spells as a BLM or using WAR's tank abilities, but a lot of the key mechanics don't get given to you until that final stretch like SMN's Trance or DRG's Blood of the Dragon.
However, if I absolutely had to pick a level, I would think you'd have your best "general idea" of how the job is going to play around... level 45, I guess? You'll have most of your toolkit by that point (though there's exceptions like SCH, where you don't get a key healing move - Lustrate - UNTIL 50) and you would've played the class long enough to get a feel for whether you'll enjoy it or not. Minus the ones that get entirely new mechanics in HW - such as the aforementioned SMN and DRG.
However, if I absolutely had to pick a level, I would think you'd have your best "general idea" of how the job is going to play around... level 45, I guess? You'll have most of your toolkit by that point (though there's exceptions like SCH, where you don't get a key healing move - Lustrate - UNTIL 50) and you would've played the class long enough to get a feel for whether you'll enjoy it or not. Minus the ones that get entirely new mechanics in HW - such as the aforementioned SMN and DRG.
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