Q: Help installing OS X El Capitan 10.11.2 or later

I own a MacBook early 2011 model with 8gb of RAM installed and just under 10gb of storage left free in my storage. I am wanting to update my machine to OS X El Capitan 10.11.2 or later but I can't due to this warning,

which will not allow me to log into my Apple ID. I go into  the app store settings and no matter what I try to change (besides the boxes where you can tick and untick) the settings automatically reset to this:

what can I do to stop the loop or how am I able to sign into the app store without the error occurring?