What do children in the US do in weeks before Christmas?

Bug the hell out of their parents about what they want for Christmas :) JK

Traditionally Children are starting their Winter break from school which usually consists of 2 -3 weeks off.

We put up our trees and decorate them

We visit local Christmas Tree farms/ Light shows / etc.

We do alot of shopping

Arts and Crafts

If it snows we usually go sledding or ice skating

We visit family and exchange gifts