Ecommerce android app

my client has a requirement of making native android and ios app for the ecommerce store based in opencart cms. My question is, how can I dynamically load the main screen content in the app like banners, sliders etc which are subject to change every day.

I am new in the app development. Please suggest any ready to use CMS for delivering dynamic content to the app. Otherwise, please guide me on how should I approach with building this app.

P.s. i am an experianced web developer with basic android app building knowledge.