UART implementation using MbedOS

Hello,
I’m working on an existing project that runs MbedOS on a STM32F103RE. I want to add a SiLabs BT Mesh module and communicate with it over UART. I have no experience using the UART driver so does anyone have any advice and best practice for this to help me get started.

My goal is to use a mobile app to connect to the module over BT and send it control messages for example to turn a light on/off, a simple thing at first and then want to add more functionality later like dim the light or play a sound, etc. However, first I need to get the communication over UART to the module working. The commands I will be receiving from the module will be text strings which I will use to turn the light on/off. Eventually, I will also be sending text strings back to the module so it can send to the mobile device and the app is updated to display the state of the light, etc.

Appreciate the help!
Thanks,
Alex