The course is meant to be interactive, which means that you should try out the embedded code snippets. You can edit them and run them from your browser :) However, if you really want a PDF, then use the print page[1]. It will let you produce a ~210 page PDF with the entire course.

For learning Rust via a non-interactive medium, I recommend the Rust Book[2]. It has all the narrative that the course material is missing.

[1]: https://google.github.io/comprehensive-rust/print.html

[2]: https://doc.rust-lang.org/book/.