how do you know which class is which like the symbol wich is the one for poko priest in the game?

Poko Priest - Orb/Ball
Dende Priest - Scroll
Shadow Knight - Axe
Dark Warrior - Claws
Swordsman - Sword
Fighter - Pole
Turtle Hermit - Wand
Crane Hermit - Fan
Ultimate Majin - Trumpet/Instrument
Grand Chef Majin - Lollipop/Food
Karma Majin - Mask
Plasma Majin - Drums

When you hit lvl 30 and talk to korin to choose your master class 2 weapons will appear depending on what Race & starter class you have chosen. The list should help you.