I’ll keep it simple. To accomplish what you want to do you’ll need to know the following:
- one general-purpose programming language (Ruby, Python, PHP, etc)
- one relational database system (Postgres, MySQL, Oracle, etc)
- one web server (nginx, Apache, etc)
- one deployment operating system (Ubuntu, CentOS, FreeBSD, etc)
- one version-control system (git. don’t bother with the etc)
Then you should be able to become a full stack developer. Hope that helps and have a great day!