UART1 serial communication

I want to use UART1 on beaglebone black to send a string of characters to a arduino. As far as I can tell, I’ve been able to correctly mux uart1 pins by using these instructions →

Now the problem is that I do not know anything to do with it. Can you can help me by pointing to a c++ code to output data through tx at certain baud rate. Also, let me know if these instructions are missing anything.

-thank you