Looks interesting. Worth exploring, IMO.
It’s better to take a look at what an API is at a fundamental level.
You could use a library that allows you to plug in data and generates charts for you. Some recommendations can be found here:
If you’re looking to create your own custom visualizations, D3.js is great. In fact, it’s what some of the most popular charting libraries are built with. There’s a significant learning curve with D3, though.
No worries on that front, I get confused about terms all the time.