I would call such a person A
***DIGITAL NATIVE***.

I see them every day. 
Most of my students are 'digital natives'.
I am not. I'm a digital immigrant.

Here's an example from Reverso.context.net:

For the so-called Digital Natives, it is quite obviously looking for products online, compare and buy.

According to Wikipedia:
Digital native is a person that grows in the digital age, rather than acquiring familiarity with digital system as an adult, as a digital immigrant.
<https://en.wikipedia.org/wiki/Digital_native>