Help with damage scaling

Hi. Im new to PoE and im having a real hard time with scaling.

I have 3 chars for now:

-Ranger

-Witch

-Marauder

With witch and Ranger i kinda get it. Damage with bows, projectile speed and such. Witch more of the same with spell or elemental damage but im having a hard time finding wands with good options so im using 2 maces.

Now with marauder im kinda lost. I got a lot of passives that grant me physical damage but dont see any elemental damage around. Just stuff that boosts one or two handed. Damage is there im using vulcanic fissure and smite. But idk how those skills scale and if getting physical dmg is only boosting my autoattacks or skills scale from there. Can someone give me some hints?