How to start studying telecom and communications?

Question

Telecommunications

Good afternoon, I am a 3rd year student majoring in instrumentation and control automation.
I decided to decide a little about who I want to become, I started looking at specialties for a master's degree at another university and realized that I was quite interested in the subject of telecom and communications (including optics, mobile communications, and so on). The prerequisites say a bachelor in specialties related to electronics and electrical engineering, so in principle I fit, but still I would like to start learning something on the topic on my own at home in order to achieve better results as a master student.
Actually, as I understand it, the specialty is not as in demand as a software engineer, but in general, there should be no problems with employment, right?
In general, I would like to hear if it is worth it, how promising it is in the CIS countries and abroad, what are the pitfalls (for example, I am a careerist and I would not want to sit as an ordinary engineer for 20 years) and most importantly, what topics and books worth starting. Maybe there are some computer simulation programs to practice at home a little.

We study all kinds of circuitry, microcontrollers, microprocessor programming, design and assembly of devices, etc. From school I was very fond of programming and planned to get a job as a web developer even before graduating from university, over the past year I have been intensively studying JS and RoR, but it was not easy for me and I realized that as a programmer I reached my cap, of course there were inclinations There are, but they are more like a hobby.