I learnt Spanish like this. Mainly finishing Duolingo and downloading some textbooks and doing a few MOOC courses and listening to slow podcasts, and then watching basic movies.
Once I got to the point I could watch movies and TV, I would watch a movie almost every single day.
It’s a lot of work, but to get to the point of speaking and listening it is necessary.
It took about 2 years in total - and then I started a job working in Spanish.
The answer is nuclear power.