How hard is it to become and emergency department nurse? Is there a high demand for these kind of nurses? is there a lot of over time for these nurses?

I am an emergency department nurse and in my hospital, we are not a trauma or a burn center so there are several types of patients that we ship to the other hospital in town. I work in a town of over 100,000 and in a hospital of almost 400 beds so i am not in a small facility(not as large as a major urban hospital though). Unless you work in an incredibly and critically understaffed hospital or you are very specialized there is no call unless your boss really needs you and you can then choose to come in, you work regular hours (36 hours per week with opportunities to pick up overtime if you need extra cash). It can be either incredibly challenging some shifts that you can't wait to get over or it can be incredibly easy other shifts. There is a high demand in the vast majority of the entire country for any type of nurse as most hospitals are understaffed. You can choose to work at a hospital that sees gunshot victims, burn victims, trauma (car accidents, stabbings, etc.) or you can work at a hospital that does not specialize in these areas.