New player needing some help with leveling

[Niwashi]

While I have no actual proof of this, I think you get an experience boost once you have a level 50. So with that in mind, before you consider leveling up another class, just try to muscle through on your tank and obtain level 50.

That doesn't start at level 50. It starts at level 10, as soon as you're able to take additional classes. Your highest level DoW/DoM class uses the normal leveling rate (adjusted by any other current boosts like food or Heat of Battle), while all DoW/DoM classes that are lower than your highest —even if they're only 1 level lower— get a 50% boost to their XP rate (in addition to any other active boosts).

The only time you wouldn't have the 50% boost on all but one of your combat classes is when a later class catches up to your highest one, so you have multiple classes that are at the same level and are all your current "highest" class.