Can you recommend a good guide?

I have all three Affinity programs. I am most familiar with Designer, I use it all the time to make promo images for my novels and such. I am now wanting to make some zines (think mork borg style, super art heavy interiors). I have a quote from a local printshop lined up, and the bulk of the text written. Now I need to start laying them out, adding art, etc. so I can produce the file I will deliver to the print shop. Here are my questions, but if you have a link to a guide/video that answers all that, which you've used, happy to just take a link:

• With Publisher being book layout software, are you using that instead of Designer?
• If you use Designer, I assume are you making each page its own file. Do you then put them in Publisher? Or do you stitch them together into one PDF?
• Lastly, what settings should I use, like for the color. RGP? CYMK? Is there a standard there for printed zines, or should I ask my print shop?

Thanks!