EU citizen registering as Milano resident question

I am seeking some guidance on how to go about registering as a resident here in Milano. I have read through the commune website a few times and I am a bit stuck ( Protected content ). I can meet all the requirements for registration but there are no appointments available at my local anagrafe until January. This is well beyond the 3 months in which I am meant to register. Can I show up without and appointment? I also tried emailing my registration but have not heard back yet. My third question is how do I provide proof of employment. Is a printed and signed letter from the owner of the company stating I am employed enough?
Any advice would be greatly appreciated! Thank you.