I was programming calculators in high school. So, I naturally enjoyed the activity. For you, since you don't know yet, you need to have an idea, a goal to code

I was programming calculators in high school. So, I naturally enjoyed the activity. For you, since you don't know yet, you need to have an idea, a goal to code for. This way you can narrow down the domain experience, languages, and test environments you'll need to learn. Once you have that in a list you should source books on each subject.