Can someone explain weapon damage to me? What is the difference between 1d2 and 2d2 for example?

They're treated like dice rolls. If you have "XdY+Z", "X" is the number of dice, "Y" is the number of sides on each die, and "Z" is the bonus on top of the roll.

So the range of damage is (X+Z) to (X*Y+Z). 1d2 would be 1-2 damage, and 2d2 is 2-4 damage. Numbers tend to gravitate towards the average between min and max.

Ah I see... That was more confusing than I thought lol

My explanation was very math-y, but it becomes easier to grasp if you think in dice. Roll X number of dice, and each die has Y sides.

what would 3d1 be then?

that would be the same as rolling  three one-sided dice, so it would always do three damage