Apache Beam Tutor for Java Pubsub Sink

I've previously dabbled in Apache Beam and am looking for a tutor to guide me in its application with the Pubsub Sink in Java. I'm at a beginner level in Java and my primary goal is to grasp the fundamental concepts of Apache Beam for Pubsub Sink operations.

Key requirements include:
- Teaching basic Apache Beam principles, especially in the context of Pubsub Sink
- Assisting me with Java programming as I aim to apply these concepts
- Clarifying any uncertainties I have regarding Apache Beam, Java, and Pubsub Sink using Pipeline
- Providing practical examples and exercises to reinforce my learning

Given my current skill level and learning objectives, I'm seeking a patient and knowledgeable tutor who can break down complex concepts into simple, understandable parts. Your ability to guide me through exercises and real-world examples will be essential for my understanding and retention.