I am new to the world of web development. I know how to use PHP and so I can do that just fine, but I am a little behind on "modern practices". Last night I went ahead and used the LightOpenID library with CodeIgniter to create a login section on my website. The user clicks log in which takes them to a login page with a Google "log in" button. That button uses the URL generated by LightOpenID to direct the user to the Google "Account selection" page which asks for permissions/etc. It then redirects the user to my website where I write their details to the database for future use - like a "silent registration feature". I store their first name, last name, email and OpenID. I then create a session for the user and the user can now browse my website. Super simple.
The reason I felt like I should explain that is because I wanted to point out how "little" I want to utilize the users account. I just need them to sign in with Google for authentication. Google's OpenID>oauth2 migration page and all of their migration examples (which are a little beyond me) explain Google+ authentication for the purpose of retrieving a users friend circles and other social junk. I don't need anything this complicated, all I need is authentication.
So I was wondering what method I should be using now instead (Google says use oauth 2, but not "early oauth 2".. I have no idea what the difference is. They also say that I should only use Google+ now) and I am wondering if you guys can help me find a simple library that handles authentication for me