MacBook Pro mid 2012 2.9GHz i7 13" OS X 10.9.5 , safari 9.1.3 , App Store version 1.3 (201.7)

I first wiped the Macintosh disk to get the computer back to "Factory reset" I followed directions from apple so I know I did that correctly, upon 1st startup after that I went to software updates & installed them all (the versions OS X 10.9.5 , safari 9.1.3 , App Store version 1.3 (201.7) are currently what the Mac is now running) I know they are outdated but when I Click the apple icon & "software updates" the system says there are no new updates - I cannot sign in to the App Store which appears to be outdated- when I try to sign into the App Store it says my login is wrong (I know its correct because I can log into iCloud with the same login on my other devices) I cannot enter the 2part authentication code from my phone into the App Store during this process because it is outdated & no box to enter a code comes up - I cannot create a new apple acct on the outdated App Store either it says the action cannot be completed right now - therefore I cannot update safari because I cannot login to the app store to download it,

I was able to download Google chrome browser so that I could try downloads off of the internet,

I looked up later OS versions that should work for this model, downloaded the OS files & ran the installers,

at the end of the process it says that it was successfully installed but when I go back to "About this Mac" tab afterwords it still says OS 10.9.5 - I am completely stuck now, I have a perfectly good laptop that I cannot update in any way rendering it completely useless.

If I can't update this I am NEVER buying another apple product again this is completely ridiculous.