I have a question about DCC in Z scale. I have an NCE starter set and want to know if I need to reduce the voltage and amps or does the decoder in the locomotive do this?

In this case we believe it would be best to contact NCE directly and provide them with the specifics of your system as well as model and brand of decoders you have. As NCE doesn’t make one of the drop-in decoders made for Z scale, better to err on the side of caution and get this information directly from the NCE. Here’s the contact form link on their site: