There are various ways to learn Selenium Java, but if you are a beginner, I suggest you go with instructor-led training. For that, have a look at the video below. This video provides a brief understanding of concepts of Selenium and Java. At last you will be able to learn some interview questions as well.
Along with training if you are looking for certification then do check out this Selenium Certification Course offering by Intellipaat. This training help you to become a certified professional with all the required skills.