Should I use Restful Application Programming (RAP) or Cloud Application Programming (CAP)

Hello everyone, I am a beginner in SAP and everything is new to me. I have to create an app and have to choose between RAP or CAP and I don't know which one to choose. I'm going to create a training management app to facilitate training within a company. I need to implement features like:

• Sending emails
• Creating a Word/PDF document
• Creating outlook appointments (if possible)

Thanks

Assim