What you choose is really up to you, but if you're avoiding Virtual Machines, Azure provides Web Apps (part of the App Service PaaS offering). I have no idea what your subscription supports, but Web Apps allow you to push your code up without concern for underlying OS (thought it supports both Windows and Linux, in case your app has OS-specific dependencies). Simple to scale up to higher/more capable tiers, and out to multiple instances (the features, and scaling, have differences for the various performance tiers). Note that the Linux variant is in preview, though both variants support PHP. You'll be able to push your code through an SCM provider (e.g. github) or via ftp.
Outside of Web Apps, you'd have:
- Cloud Services (web/worker stateless Windows Server VMs)
- Virtual Machines (Windows/Linux with many supported variants / distros)
- Service Fabric (a managed microservice offering)