I think we should not compare Selenium and DevOps. Although both the tools contain their own credibility and choosing to learn or to get a job has fundamental differences. If you want to learn course easily then check the background of technology,
for example, if you are a JAVA guy and you are familiar with JAVA then check google trends for Selenium Job Market and learn Selenium course who are providing it with Realtime experience. If you are a Linux user then look after DevOps With AWS Training and check google job trends in India for that as well. choosing easy technology does not matter that you are going to place and earn good pay. If you like reading you must read the following Selenium Tutorial. You can also watch the below-mentioned Selenium video tutorial to learn it. . I am also mentioning the DevOps video Tutorial which you can watch to know it better. .
If you wish to learn more about DevOps, visit DevOps tutorial and DevOps Certification by Intellipaat.