I'm starting the nuvaring: questions.

Abigael
So I am about to start the ring and I have a few questions.
-I got it a month ago and my period ended before I could put it in, so I put it in the fridge. Should it still be okay to use? (Only had it out of the fridge after I picked up my prescription for four hours)
-what cycle day should I insert it?
-how long does it have to be in before it is active?
-side affects?
-how effective has it been for those using it?