My MacBook Air is having issues that a hackintosh computer might have, but the machine is bone stock.

Hello! I have a 2012 MacBook Air A1465 that I purchased from a state agency auction, which was running Ubuntu when I purchased it. I have since wiped it, and installed Mac OS, and noticed immediately that the computer would not connect to wifi. I reinstalled the OS and updated the software, and that did not fix the issue. I swapped the Airport Card and it didn't fix it, so I just ordered an external USB wifi adapter, and that worked. I just assumed the machine had some kind of board issue that was causing the wifi to malfunction, but now it is giving me the "Your device or computer could not be verified. Contact support for assistance" error on the app store. I went in to System Preferences>Network and removed all of the options on the left, restarted, that didn't fix the issue. I have deleted both the cricache.db and ocd-cache.db files, restarted, and nothing changed. I went in terminal and tried to push this update "sudo softwareupdate --background" that Apple released to fix the ethernet and wifi issues on some machines, it did nothing. Also I have wiped the SSD and reinstalled 10.10 and 10.11 and had all of the same issues each time.

I am not sure if I am posting this in the right place, but I thought a community of people building computers and bypassing all of Apple's restrictions and loading their OS on their custom builds was a good start. Is there a way to essentially re image the machine so whatever is corrupt can go away and I can get a clean version back? Thanks in advance for any help.