SVGs generated from the web, and any SVGs from Inkscape, will be in the RGB colorspace. To convert it to CMYK for printing, there are basically two major steps: Converting the SVG to a PDF, and then converting the PDF from RGB to CMYK.
Note that CMYK and RGB are literally different types of color; there is not and cannot be a 1:1 correspondence between their colors, so if you need to regularly design for print you should be using CMYK from the beginning (not tacking it on at the end) -- and for that, unfortunately, the only option is Adobe Illustrator.
Anyway, this is what worked for me to convert an RGB SVG to a CMYK PDF with a specific DPI.