itunes 12.8.3.1 Won't connect to iphone 13 pro max

Good evening,

I don't subscribe to Apple Music...I have curated my music in itunes for years and want to be able to sync it with the new iphone 16 pro when its released. I have an m1 Macbook and itunes match is on there but all of my music syncs to a 2011 imac running high sierra 10.13.6

When I plug my 13 pro max into this computer it tells me I need a software update...not an ios update. When I select that update it tells me there is a network problem. I have tried this for months and same error. In reading through the support pages others suggested reinstalling that version of itunes over the current version...tried that and same error.

tl:dr When I get my new iphone 16 pro how do I go about getting my itunes library onto that phone if I can't currently sync this phone? If I use migration assistant will that copy over music and video files as well?

Thanks in advance