I would strongly recommend an airband radio - for (a) listening to the big-guys and practice beating them to the readback and (b) listening to those at "your" airfield and elsewhere.
Quite apart from liking to listen (OMG am I admitting this in public?) I found that my "sad bas*ard" radio was an invaluable tool in getting it right(er) when it came to my own RT.
At the time I was doing my PPL I was working as a negotiator of fairly complex contracts in banking - most of my role was on the telephone so the exchange of information/key data over a telephone was commonplace for me. A bonus as the transition to radio was, essentially, no biggie. I was, however, learning at an airfield which is only a radio service and at the time the owner of the airfield who ran the radio had his own wonderfully idiosyncratic way of working [RIP Chris Freeman] so this meant that when I came to speak with Thames Radar for the first time my heart was in my mouth. I have to say that having spent some time with my sad bas*ard radio, having listened out on frequency before making my call on the day, having my checklist for the call pre-printed and ready to rock-n-roll I had eliminated most of the uncertainty - all that was left was me broadcasting to the airwaves. My first call was clipped, efficient, seemingly spot-on (judging by the instructors reaction and the ATC response) and what I heard from ATC was what I expected (having listened out) BUT ..hehehe... having been so relieved at the exchange being so normal I totally forgot to reset QNH hehehehe
Key is practice. Understand what it is that ATC will expect of you, have your data ready at all times ... being in the air is a fabulous privilege and you are surrounded by an infrastructure designed to keep you safe but you have to play your part. The reality is that everyone involved in aviation wants it to be a successful "event" and are all there to help make it so!
Happy landings!