If the device is new, then it should be under warranty. You may want to contact the manufacturer.
You should also try starting it up in "Safe Mode" and see if things (except apps you installed) work. If they work in "Safe Mode" then you have something on the device that is the cause of the issues. Bad app, virus, malware, etc., that will have to be removed to get it working correctly.
To get into "Safe Mode" please do the following.
1. First turn off the phone.
2. Next press and hold "Power" until you see the manufacturers logo on the screen, then release the power button.
3. "Quickly" press "Volume Down" and hold it for few seconds until you see the message "Safe mode: ON" or something similar.
4. If you wanted disable it, simply repeat the steps above, and you should see "Safe Mode: OFF" rather than on.