If you are well versed with Selenium then you can consider the below-mentioned points directly but if you are a beginner then I will suggest you first learn Selenium, you can take up the following Selenium Training Course and then you do not need to look for anything else and you can apply for jobs after successful completion of the course.
You should practise Selenium with at least 2 bindings E.g. Java and Python.
You should learn Selenium Json wire protocol details.
What is the difference between selenium versions like IDE, RC, WEBDRIVER
and understanding their architecture using json wire.
What is Selenium classes/interface/methods hierarchy from top to bottom?
E.g. RemoteWebDriver, Webdriver, By, BrowserDrivers etc, a neat diagrammatic representation should be known.
Selenium GRID implementation for local and remote nodes.
Selenium integration with different tools like JMeter, cucumber, AutoIt,sikuli, Jenkins.
ngWebdriver for angular websites.
Selenium frameworks like page factory, hybrid etc.
Using reflection in Page Object framework for creating pages dynamically.
Using TestNG listeners and WebDriver event Listeners.
Selenium usage with Docker.
If you are preparing for the Interviews then I will suggest you must have a look at the following Selenium Interview Questions. Here is the video by which I came to know all about these things. .