If you know that you either only want to work with data or exclusively on the backend, learning Python is the other option that is good for beginners.
There are plenty of high-quality free options to get started with coding. freeCodeCamp and Codecademy are excellent choices and are great to set your foundation.
What To Learn Frontend Development
Modern UI development has gravitated towards a component model with three libraries as the primary ones used by professional frontend engineers— React, Vue, and Angular.