Write a Test (Java)
Follow the Add Appium java client to your test framework tutorial in order to connect the library to your test framework sources.
The Appium Java client has dedicated classes to support most of the official Appium drivers. For other drivers you could simply use the AppiumDriver class or build your custom derivatives from it. Check the Drivers Support article to learn more about the current driver class implementations.
Follow the Usage Examples article in order understand how to invoke Java client features from your test framework.
Once you've managed to successfully run a test, you can read on for some next steps to explore.