Drupal Developer Trio
Drupal Developer Trio covers layout options and theming with Twig on Day 1, as well as basics for developing custom modules on Days 2 and 3, for anyone who already has a good grasp on Drupal site building.
Each segment of the course is also offered as a separate unit for developers who may not need both frontend and backend instructions:
- Layout & Theming
- Module Development
https://www.drupal.org/node/3274132