How to use ionic to consume Yii2 Rest Api

I am learning about IONIC2 framework, Still I am very newbie however I have some questions:

I am using Yii2 as backend and Admin setup. Then Ionic as frontend. I want create an hybrid App, I mean. I want have:

a. Web app

b. Mobile app

My questions are:

  1. How do I consume Yii2 Rest Api

  2. How do I bring a fresh theme (template) or even do bootstrap in Ionic2.