On a sidenote, I was like 14 when I migrated from ham/CB to commercial radios. A lot different then though.
I was more into hardware, most radios had chrytal control. I was well into commercial when radio and embedded control were married.
DSP was theories at a few universities.
For the OP though, a LOT has changed, Radio CPUs are now mostly32 bit multi core, On board hardware DSP, several link layer digital modes,
Trunking, encryption, all fairly new.
It took me all these years, reading studying, trying to stay on top of fast paced technology and computers.
Like a VW trying to catch a supersonic jet.