"Coding" is a huge world and in my opinion in today's world the term "coder" is too abstract to mean anything in practice (other than someone who writes code among other things). What we mostly share is really just the basics. You can improve your fundamental knowledge that will help you learn, understand and navigate through the differences quicker.
But not just from field to field or job to job, but even from just one task to another task, a coding session can be totally different from another. The "actual typing of code" is just one mechanism.
If I understand you correctly and you're specifically interested in the act of typing code and understanding what it does, then maybe you might be more into coding puzzles or you could learn more about algorithm design. Else, if your goal is to see more output by coding, then progress and experience is the only way. I don't have ADHD, but I have difficulties in finishing personal coding projects, too. Coding for work definitely helped with that. Before that, the biggest improvement I found was to use more Git (/version control in general). Helped me a lot to organize and see my progress.
Do the math yourself. It might take about 4 years to get the correct result, but the truth is worth that time!