setting for printing in Fresco

Nicole,
There are online tools for that, but from my experience I can't say they are trustworthy. Specially when it involves sending stuff to print shops, where mistakes can be really expensive.

Converting an RGB image to CMYK shouldn't be a big deal, but it involves using software that understands colorspaces and does the conversion properly. A good conversion will take care of black generation (i.e.: how to turn RGB black into black ink, whether using pure black ink or a combination of CMY/K to produce a richer black), the total ink coverage so the printed page gets rich colour but also dries reasonably fast, etc.

The online apps that offer conversion to CMYK often fail even in the most basic aspects, as you don't have control over those parameters, rendering intents, etc.

Also, using an automated tool like those gives you almost no control and you can't inspect the result, so I'd stay away from them.

Asking a friend or colleague who has Photoshop to give you a hand is what I'd do. Using the "convert to profile" command in Photoshop using the color profile provided by your print shop is the way to go.
If you're looking for free software for that, Krita has that feature and it does a good job.