Facebook connect using django rest framework and angularjs?

Im developing a website in which the user can signup using facebook connect, when he signup we will collect all his personal details from fb and store it in a user table. This user table id is used as foreign key in many other tables. My questions are,

1. How can I implement fb signup using angularjs and DRF.
2. Once the user logs in how can I get the corresponding data from related table since I will pass only the authentication token(Do I need to get user id matching the auth token?)
3. We collect all his details only for the first login, how can we find out whether the user is already registered or not?
4. Is there any valuable material available online for this?

Im using python-social-auth and oauth for the above, but they are very confusing.