US Immigration from Canada

So I got my K1 after a long wait. I'm finalizing my move, and I learned that Canadians have to register if they intend to stay in the US for longer than 30 days (iirc).
Does anyone know if I need to register with USCIS?

I am looking for some help/guidance with our current petition. After 3 long months, my fianc and I have received Packet 3 from the Montreal Consulate, and are currently waiting for the Police Certificate to arrive so we can submit all documents to continue with the process. However, our I-129F approval expires very shortly, and we will certainly not have an interview scheduled before the approval expires. Due to most of the 4 month period being taken up by waiting for the consulate to give us our next steps, I have tried requesting an extension both through email (to Canada.Visas@gdit-gss.com or Canada.ACS@gdit-gss.com) and phone number (438-793-1947 or 514-398-9695) and get the same response back that those contacts are only for interview scheduling service, and to go to the website for the correct information on how to contact properly. This is the contact information the website displays, so we are stuck in an infinite loop without being able to get ahold of anyone who can help. Does anybody else have any other contact information to speak with someone or experience with how to do so? If not, is this something we should even be focused on doing? (Most forums and videos online state that once we complete all documents and attend the interview, that they will automatically extend the validity there and then). Consensus says it's not something to be worried about, but I thought I'd ask for help rather then let it be and show up just to be denied as we are this far along in the process. Thank you!

Hi, my fianc and I have finally had our case updated to "Ready" at the Montreal consulate. We've seen conflicting information on if we should wait to do DS-160 , schedule medical appointment and actual interview until we have received something from the consulate, or if we can go ahead since the case is now "Ready". We have not received any email or mail updates from the consulate at all, so looking for some clarity because we do not want to leave it sitting too long. Any other useful information or tips, Montreal specific or in general with the process, are welcome also, thank you!

Hi guys! Im not aware if this question has been answered.

I am a Filipino Citizen beneficiary on a work permit in Canada. Before my medical exam, I have heard about the immunizations I need to get.

is it enough to show a record or card of my immunizations when I was young? My mother will send it to me here in Canada. That way, I only need to get a flu shot or updated tetanus shot.

Thank you in advance!