Comment by iSloth
Same background as me, however I moved into cellular/mobile - not really any official routes I know of in the industry, certainly not like a Cisco track.
Typical route is work at a Telco or IoT company as Network Eng or Developer and naturally pivot into telco learning on the job.
Vendors will run training courses when you buy their kit which helps a little, but it’s mostly self learning or on the job.