DevOps is more like a culture that helps in reducing the gap between the developers and business operations. Working in DevOps in different phases might require you to work with different tools and technologies.
Here are some of the basic prerequisites to learning DevOps:
Knowing Command Line Interface
Knowledge of a scripting language
Basic understanding of Linux/Unix concepts
Working knowledge with a text editor
Basics of Web Servers including Apache, PM2, etc
Basics of Databased like MySQL, MongoDB, etc
These are just a few of the things that you can start learning before you go with DevOps. You might also require a few other skills and technologies to move to the further level.