Blackberry has the best operating system the broader world may never have the benefit of using. The QNX code that has now influenced the Blackberry OS is also used for cars, power plants, and other critical systems. It will live on, but eventually the design may find its way into more devices to produce more reliable systems.
Working at a company doing software development for the next 10 to 40 years is a great career. It is a great career path that can return huge dividends to you in terms of personal development and the ability to have a huge impact on an organization. Starting your own business is also a great way to apply software development to problems that can produce solutions of value to people. There is a lot of risk with a start-up but you get to decide how you will go about technology more than you would at a company and you get to nurture the full vision of your ideas. That is a huge draw. A career at a company meanwhile is the opportunity to see steady progress in the use of skills and build enduring relationships. Having such choices is a good thing.
Start with understanding the software development lifecycle. Do a web search for software development lifecycle as there are tutorial websites that explain it well. Next, you can start coding without any additional instruction. You may not become good at first but diving into writing code can shake off any fear of writing code. Once you are comfortable writing code, even if it is bad code, you now know you can improve. How do you improve and become a software developer? Use the Web to connect with mentors who can show you the ropes primarily through open source projects on GitHub. Another way is through schools that are either bootcamps, vocational institutes, or universities. Whichever way you go, find the best software developer you admire and work towards imitating them until you come into your own way of doing things. Even then, never stop learning from others and always keep practicing and learning.