If you really want to learn some C or C++ you still can!
Not much has changed and the "10 years old" documentation is pretty relevant today. I found the code examples from
https://github.com/pmartin/pocketbook-demo/tree/master very helpful. For the SDK usage, I followed
https://github.com/Skeeve/SDK_6.3.0.
I guess it should be possible to connect to PB's sqlite databases similarly to the scripts from this thread.
Also, there are some projects allowing you to write programs in other languages: