Help decide my class

[Bixby]

I read that jobs share levels with the main class, so if i level either pug or monk to 50 it will level the other as well? meaning you don't have to level pug AND monk to 50?

Correct. The base class is the only thing that actually levels. The job, which is literally a piece of gear (soul stone) you equip while on the base class, just follows along with the base class' level.