Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Triebel's books are nice but hard to read. I would recommend on this topic the Springer Grundlehren book Fourier Analysis and Nonlinear Partial Differential Equations by Bahouri, Chemin \& Danchin.
You should clarify your expectations for Egorov theorem in that class; what is likely to happen is that the remainder will have the same order than the main term.