Hi there, @reheftma ...
I don't know of any built-in Canvas function that lets you search for content within your course. However, there is a third-party LTI external app called Atomic Search that might meet some of your needs. This LTI app may have a cost associated with it, so be aware of that.
I know this might not be the exact answer you were looking for, but I hope that it will help in some way to answer your question. Thanks...take care, stay safe, and be well.
I do not know of any such function via the API, but you can get all the files, pages, announcements, and quizzes via the API and search this content. For a course that I have with a very large number of pages (~800 of them), I keep a copy of the contents of all of the pages locally in a directory and then can each use grep to search them. The program I wrote to get all of the pages is cgetall, see https://github.com/gqmaguirejr/Canvas-tools