Why would you reuse a design? I just said that I’d be happy to help as well
If it makes you feel better, CMYK and Print is like black magic for me too. Different printers might require different standards so it really depends.
In general, any Vector File in PDF format with rasterized text in CMYK should be good. If you want to print raster (pixel based images) 1200 DPI should be safe for most cases but I don’t see why you need to do that unless you want to print a photo.