Brand registry question and Error 8572

Hi guys!

Complete amazon newbie here! I am super frustrated right now because I have been getting this error : 8572 and I have been going back and forth with amazon a ton of times with no resolution yet.

Couple of questions

Do I need to enroll in amazon brand registry to actually create a listing and sell on amazon?

If yes, then do I need an ASIN No to be enrolled into the brand registry? Doesn’t that mean I need to have a listing on amazon sellers account?

I am located in canada. Therefore I did register my trademark and have a pending registration number from Canada CIPO but since I plan on selling on Amazon US, I bought a UPC number from GS1 US. is this correct?

Please do help if you have any info. This will greatly help me!