Children's Fantasy Book with time traveling

This is a book I very vaguely remember. I remember reading on a school library Kindle that I borrowed in middle school in 2012 or 2013.

The plot centered around a kid that could slip through time and slightly affect the past. I remember a specific scene where he was sitting in a restaurant, slipped back in time and someone in the past saw him and his table of friends hovering above the swamp eating noodles. Then when he came back, there was a painting in the restaurant of some hovering "spirits" eating noodles.

I also remember that there was some drama about the setting. The world was somehow divided into regions by these towers which created these massive energy walls. I remember the book ending with the kid taking himself and someone else way back in time before the wall to cross to the other side into a strange unknown new region.

I also remember the region the characters started in was like, stereotypical Shakespeare time period.