I don't have an iPad, but if it's anything like the PC version you start episode 2 like this:
In the games main menu click "Play".
On the next screen select a savegame, and click "Play".
On the top of the next screen select Episode 2 and click "Play"
I am a Community Moderator, and I am here to keep the Forum a fun place for everyone.
My posts represent my personal opinion. I am a volunteer, not a TTG employee.