Not familiar with I-cloud, need help

I am hoping some one could help me find my lost calender!

At the last update my 7 yeras of calendar content diseperd..

I have backed up the phone- but now I dont know how to sync- the cloud with my phone and get the content back..

I live by my phone like most people, unfortunatly I find the cloud and backing up and the I-tune store to be very unhelpful and frustrating.

Thankful for any advise.

Ginger