Welcome!
There aren’t really “coding programs”. You use either a text editor with niceties thrown in for coding (VSCode is popular and free) or an IDE, which is a slower text editor with further niceties.
What matters right now is choosing a language. That depends on the types of Workflows you want to start with, but in general Ruby or Python are good choices. Ruby is my pick for reasons I won’t go into (this isn’t the place for a flamewar), but Python has a larger community at the moment. Just make sure to use Python 3, not 2 (a can of worms not worth going into right now) if you go that route. That, however, will make it harder to share your Workflows right now because Python 3 does not ship with macOS. Ruby isn’t yet affected.
Either way, the worse thing you can do is get analysis paralysis. Start with either, you can always switch later. Concepts you learn in one language will translate to others, even if you write or apply them differently, meaning you won’t waste time if you start with something decent (Ruby or Python).
I won’t recommend a particular source for learning either because there are tons of good ones, from books to lectures to courses; spend a few minutes researching what resonates with you. Consider it part of the learning process: to be a good programmer you’ll need to be comfortable with looking things up.