consult-line
And I'm using outline-minor-mode
(setq-local outline-regexp " *//\\(-+\\)")
(outline-minor-mode 1)
Now every comment starting with // followed by one or more - like
//- Function this
//-- Function that
//--- Some important code
is treated like a heading by outline. So, you can use all the outline functions for navigating and folding.
Also you can use consult-outline (if installed) to jump quickly to a heading.
To make it even more convenient I recommend the packages bicycle and logos.
Welcome!
Try this one
https://www.gnu.org/software/emacs/tour/
After I got more familiar with Emacs I spent some time to walk through each chapter of the Emacs manual. Even if you think you know how to search and replace within Emacs, after reading the chapter about it you know even more.
And what is most often forgotten: Use the menu bar. You can find most of the basic commands and their shortcuts there.