Hi Wenona, has the device been powered off for a long time? If no significant amount of time (months/years) has passed since it was last used/charged, first you want to make sure the connection to cable, charger and power outlet (plug the charger directly, no extention cord, power strips etc.) is good, inspect all ports and clean any debris, lint etc. with the aid of a toothpick and compressed air (being careful not to force the dirt further inward). Report back once you checked all of this.
Also, according to the instructions reported [link|https://www.hardreset.info/devices/jbl/jbl-xtreme-2/|here|new_window=true] the right combination to perform a factory reset is "Bluetooth" + "Volume up" buttons, but the device should be turned on first I believe..