how much will Du see in part 1?

probably up to the end of jacobs point of view in the book, we probably wont even get to see renesmee

It's difficult to tell.
When Du look at the link cast page, we know all the other covens are going to be in it, along with J Jenks, But Mackenzie Foy won't play Renesmee...
Maybe they'll be wedding guests, though.