That’s a really good question...!
Libraries are only ‘hidden’ to the extent they won’t affect your code unless you actually invoke or call them.
They are usually provided with sample code to demonstrate their basic function, so that really that shouldn’t be a problem however there’s no harm in ‘trying’ then posting your code - along with what you didn’t understand.
The underlying concept you’re looking for is writing & testing code in isolation, then stitching the pieces together. A good starting point is to write your ‘functional’ code as functions.
These functions will generally stand alone, and can be put aside for use when needed, but managing libraries will still require some practice and understanding of what each library needs.