Retrieve User Access Tokens


Hello there. I am new to using OAuth and have questions about using it to get user information.

I know I can directly plug in my oauth access tokens from the developer dashboard, but how can I have a user ‘log in’ to twitter, so that I can use the access tokens to retrieve their data. Do I just have oauth completely wrong? I am using the TwitterAPIExchange. If I need to provide any more information, please tell me, as I am not very knowledgable on things like this.