A:AnswerUpon removing them out of the case you should hear a message that lets you know they are on. For further verification, connect it to your device (ensure that they are sufficiently charged). The light on the front of the case it should either be red or blue.
A:AnswerI had this issue. The instructions in the booklet told me to tap the headphones 7 times each and put them back in the case. They should sync. Worked for me.
A:AnswerThey usually come with more in the box when you purchase them. But you can typically purchase them separately from Amazon or another retailer like Temu. Hope this helps.