What is the DPI setting before sharpening process?
If you're printing with a specific paper/printer profile, with Photoshop or other software controlling, then your print file's color space is automatically recognized. But with printing directly from the Canon driver (printer control) you have to specify this in the "Color Settings" driver section - in my iPF5000, sub heading of "Matching".
The DPI question: I think you are referring to your print file resolution, which is expressed in PPI (pixels per inch) which is used for digital input, rather than DPI (dots per inch), which refers to analog output devices such as printers. After sizing your image, re-sampling to at least 180-240 PPI for very large prints, or 300 PPI for smaller ones is appropriate before output sharpening.
You sure picked a huge printer to learn with! And the above is only touching the surface - sharpening and color management are complex arts and sciences of their own.
Pete