I want to Enable Authentication Module for our Website

I have work experience on Nagios and Puppet and new to Python and Angular JS .

We are planning to Implement Authentication Module to our internal website . We use Angular JS as Front End . My SQL DB as DB and we are using REST API (python for coding) .

I have seen lot of posts and bit confused as they are more ready made for people who are already familiar with UI Terminology .

Whats are the steps to be taken care to Implement Auth Module .

Should i first start with LDAP queries ? Do we have any default plug in in Angular JS to enable Auth module .

Thanks