Start by checking the audio drivers in Device Manager > Sound, video and game controllers. If Realtek Audio is missing or showing an error, try uninstalling the driver, restart your PC, and then reinstall it from the ASUS support page. Also, run the Playing Audio troubleshooter in Settings > System > Troubleshoot > Other troubleshooters to see if Windows can fix it.
For the USB issue, if only one device isn’t working, try a different port. If that doesn’t help, go to Device Manager > Universal Serial Bus controllers and update the USB drivers. You could also disable USB Selective Suspend in Control Panel > Power Options > Advanced settings under USB settings. If nothing works, check for Windows updates or restore your system to a point when everything was working fine. Let me know how it goes.