how do I back up sms from moto g to pc

[AC Question]

no idea how to do this. VERY new to mobile phones but don't know how old phone is?

 

[ManiacJoe]

You may need to be a bit more verbose on what you mean by "back up to the PC".
For example, you can use an app like "sms backup & restore" to create an XML(?) file that can then be copied for safe keeping, including to your PC.
Whether or not you have any app on your PC that will know how to read this file is a completely different question.