Does anyone has an experience integrating emails/landing pages thru an API from content management system? If yes, please share some ideas or steps on how to do it.
Have you... read the Developer Docs for the Marketo Asset API? That would be a prerequisite, then you can follow up with questions.
Also, please move this thread to Products as this space is for gen'l marketing topics and your question is (extremely) Marketo-product-specific.