People who learn to program have to get used to the idea that programming languages are many, and they have to attain certain competence in
several of them.
A typical frontend dev uses Javascript, CSS, HTML, likely some occasional bash.
A backend developer probably faces the preferred backend language (Java / Python / Ruby / PHP / whatever), SQL, and has to have at least a nebulous understanding of HTML, CSS, and JS.
A devops person has to face a shell language, the Unix tools mini-languages, have enough Python or Ruby chops to handle things like Ansible / Salt / Chef, and likely some SQL to keep an eye on the databases.
This does not include smaller languages like regexps, or narrow-use languages like XSLT, JSON Schema, etc.
There's no way you learn the One Practical Language That Matters and can be limited to it. You could in past, with a Spectrum or a TRS-80 and Basic, but the times have changed.