FreeCodeCamp is one of the strong community out there. It has tons of tutorials about frontend and backend.
You can also earn certificates once you finished the course's projects
2. Mozilla Developer Network (MDN)
MDN Web Docs, previously Mozilla Developer Network and formerly Mozilla Developer Center, is a documentation repository and learning resource for web developers used by Mozilla, Microsoft, Google, and Samsung.
MDN will be your ansyclopedia if you are working on web development.
Dev.to is a website which developer community can create and share articles with each other. As the name suggests most of the contents are related with development but it can be about motivation, life goals, etc.
We always have some problems when developing an application. Stackoverflow is a place where you find solutions of your problems. You can also provide some answers to those who are experiencing an issue and get rewarded by points which are called reputation.
You are developed some projects and looking for a place to save them. Or you want to contribute with the project you love which you know it is open-source. In that case github is a place for you.
Github is your ID when it comes to development. It will show anyone what you built, what are your insterest and what are you working on.