im 59 now too, doing ER for the the past 32 years, im still in it and for the most part, I like it; don't know how long you've been out of the bedside but nursing has changed so much.....nursing care is still the same; but for the most part charting is now paperless.
There is protocols now for sepsis, MI, strokes and steps to be met. Before, we just knew what we had to do without those protocols, now its just written down step by step. So care is still the same.
Most hospitals have their own training programs for their specialty units at least where I work; they usually take in house people first and preceptorship is about 6 months. ER is not easy, theres good days and bad days. The only way to find out if you're going to find out is to just go and do it. Then you can say, I tried it. You don't want to always wonder down the road and wish should have tried it. Good Luck for whatever you decide to do.