I would say the language itself doesn’t matter as much as what application is going to keep you interested.
I would go for something that easy to use libraries that can give you visual feedback quickly.
Processing is a java library and evironment with a dedicated IDE for graphics and interactive / creative coding. I would look into that especially since you are a designer. It’s east to get started, and It’s how I started learning, by building more complex applications in it. Just keep a link to the reference page is my best advice.
The fact that it’s java I think is a plus because that would give you more fundamentals compared to starting with more more shorthand language. There is also a javascript library based on processing called p5.js that I would recommend equally.
Both have a lot of resources on line, in forums and also on youtube.