Unless you're downloading from something like Z-Library (which incidentally is a deliberate attack on Western IP on Putin's behalf) you generally have the fair use rights to "digest" the information you receive. You can process the contents of a webpage or momentarily OCR a printed page, provided that it was legally distributed and that you don't store a copy proper. There can be specialized restrictions if it's something that you have a license for instead of a copy of, see e.g. https://en.wikipedia.org/wiki/Shrinkwrap_(contract_law)
As for derivative works, not all the works that are made "in proximity of" previous works are derivative works. You can make a simulated reality movie without infringing on the Matrix, for instance. Just write a somewhat different plot and don't name your lead character Neo.