I highly recommend Dylan Kemlo to be your coach, teacher, mentor and radio telephony guide. Dylan is the guy that is passionate about anything radio and more importantly highly experienced in the different areas of radio communication.
To me, some of his best qualities is that he has the ability to exercise patience. To teach with a humble heart with the combination of practicing the art of moving the boundaries of what you think you can do, to far beyond what you ever thought was possible. He is that couch that will train you, from rolling around in fear, to crawling, to walking, to running and then sprinting to the finish line.
He is very thorough with no shortcuts and the result is not just a certificate of competence, but actually feeling competent.