Hello Asude,
What to code and what to code it in?
What a big thought! Looks like the programming equivalent of “To be, or not to be, that is the question”

Personally, I'd say it depends on the purpose at hand.
If you want to get things done in a quick / time-sensitive manner, then by all means go with whatever language +libraries you are more proficient in. This day and age programming time itself can be said to be more scarce than computing power (gladly!).
If you want to learn, there's usually nothing more productive than the hands-on approach by using your target language to code programs in an increasing difficulty fashion.
This approach is what works for me.
Cheers!
Vic