I unchecked the ical holiday calendar the calendars under the regular google email address so now I am only using the google calendars that show up in Exchange do avoid duplicates. 

I think you also wanted to know where to find other Google calendars.  I found those by going to Google Calendar on my pc, in the left side panel click the pull down menu just to the right of Other Calendars, then choose Browse Interesting Calendars.  Not sure how to locate those directly on the iPhone, but using my pc works for me.