Question

could some explain what will happen from a supply/demand side if factory that makes pens and the demand for the pens decline, and there are more people willing to work due to a recession.

Answer 1

Take a shot, what do you think.
Start with a simple supply/demand diagram then shift the curves as you think. e.g., closing a factory would shift the supply curve inward.

Answer 2

the demand would shift inward due to the decrease in demand, but i was alos thinking that more workers would increase the supply
correct?

Answer 3

If wages are flexible downward, I agree. More willing workers means the factory can employ all the workers it needs at a lower wage rate.