1. RoadMap.sh
Link : RoadMap.sh
In my opinion, this is one of best repo if you need a roadmap to start of with any tech stack from the following
I have referred to this repo many a times to start off with anything new , this doesn't actually make you a pro but is a great starting point for anyone who is clueless about where to start from. You can always run the repo on your local , but here is there website with the code hosted https://roadmap.sh/
2. Build your Own 'X'
Link: Build your own
This is one of the coolest repos out there for people who love to build stuff and learn at the same time , this repo has "How to guides ". You can even build your own OS , isn't that something
This Repo is a project hub as some would say, really nice projects to boost your resumes and profiles
3.Free Book Foundation
Link :https://github.com/EbookFoundation/free-programming-books
This is the best place to get relevant programming books and tutorial related to a language or framework. The best thing is that it is maintained by devs of the world, so the stuff here is super relevant.
Have FUN Leanring !!