Im a mega newbie at Ionic 2 and Angular 2, but i have quite a bit of background in PHP.
I have built my API in Laravel 5.2, at the moment, i have a login URL as follows:
I am not sure what exactly you mean with "make the login form actual communicate with the API".
If you mean the actual http communication you'd need to understand
Observables. If you search for those terms you will find plenty of information and examples.
If that is not what you mean please be more specific.