You can't "connect your device to a pod" - the pods connect themselves the router and the devices connect themselves to either the router or a pod depending on which they find best. The router and the pods together equal one network to connect to.
Are your pods connected to the router? If the little light on them is flashing, they are not connected. If not connected, following the install procedure in the instruction book or on the xFi app go to More > Add a Device > Xfinity Device > xFi Pods.
If that doesn't work, please repost with what happens and what exactly isn't working right. Good luck.