AirPod problems.

Hello. I just purchased a pair of Apple AirPons on Saturday, September 22, 2018. I have been having off and on problems with them. First, in order to pair them for the first time, I had to reset all of my iPhone's settings. When I tried to pair them after unboxing them, I kept getting the message "connection failed." This also happened when I was forced to reset the AirPods. They wouldn't reconnect. Another problem is that sometimes, when I put them into my ears, the audio route does not change, even though automatic ear detection is turned on. I purchased them from Walmart, as they are an Apple reseller. Can anyone help me?
Thank you so much.