Question

would an increase in volume cause a shift to the side with more gas molecules or less? Why? how does it al work?

Answer 1

Increasing volume reduces the pressure. The system at equilibrium (presuming that is what you are asking about) will shift to the side that has a greater number of gas particles to try to increase pressure. If both sides have the same number of moles of gas particles in the balanced equation, it will not shift unless the volume change is abrupt, causing a temperature change.