Hello everyone!

I am new to Falcon 4.0 and this is my first message. I purchased and installed Falcon 4.0 from Steam five days ago in order to take advantage of its modern update of the Benchmark Sims, of which I downloaded and installed the current version 4.36. I believe I have all the original manuals, especially the Dash-1, Main Checklist and BMS Training. I started the "Ramp" mission three days ago and I struggled to get to communications - and here I am stranded: I absolutely cannot understand how to communicate with the control tower and everything else - I am in total confusion between DTC, COMM1 & 2, UHF, VHF, frequencies (I see that I can only set one, but in the briefing there are many ...), etc.
I managed to start the engine, I can get to the runway and take off, but if I can't communicate with anyone I don't know what I'm doing ...
Please, simple help! I would hate to give up on this beautiful simulator with its engaging dynamic campaign and one that reminds me of the much fun I had thirty years ago with its venerable predecessor: Falcon 3.0. Thanks!