Help my data connection isn't working after factory reset?

[Android Question]

I had to do a factory reset due to some apps, like my whatsapp, not working.
After a few hours of struggling, I got my apps back but my data connection isn't working. I can only connect to WiFi.
I tried turning the data connection data widget on and off, switching back and forth from airplane mode. Nothing is working.
It stays blank.
Can someone please, please help me fix this?
I have a Samsung note 4 by the way.

 

[Hadron]

If you have a cellular signal but no mobile data try checking your APN (Access Point Names) settings. You should find them in the mobile data settings, and the values for your carrier can be found through their website or a Web search. That's the first thing I'd check.