Why won't my iPad apps sync when connected to my computer?
The obvious thing to try first is to reset your privacy and location preferences. You will then be asked to trust the iTunes/computer drivers (and asked to set privacy settings elsewhere as they come up). 


https://support.apple.com/en-us/HT202778


At that point, the issue is almost certainly on the computer end with iTunes or iTunes settings or the os/usb hardware and drivers. Starting with a review of iTunes settings and looking for specific sync errors would be good to start. 


https://support.apple.com/en-us/HT201253