Pull Requests Courses

Getting Started with Open Source & GitHub
Traversy Media via YouTube

GitHub Concepts
DataCamp

How to Contribute to an Open Source Project on GitHub
egghead.io

Version Control in node.js: Update Your App with GitHub
Coursera Project Network via Coursera

Git tutorials for Beginners - Complete Course
Udemy

Guided Project: GitHub and GitHub Branches for Beginners
IBM via edX

Breaking Down Silos and Fostering Open Collaboration in Organizations
ChariotSolutions via YouTube

Getting Started with Azure DevOps
NDC Conferences via YouTube

Intermediate GitHub
Tech with Tim via YouTube

Hands-on GitHub for Every Developer with Most Important Tasks and Tips
Prodramp via YouTube