For live training, I can not recommend Guru Labs[0] highly enough. They offer many courses, but specific to your question, lots of container related courses[1][2][3][4].

[0] https://www.gurulabs.com/linux-training/courses/

[1] https://www.gurulabs.com/linux-training/courses/GL340/

[2] https://www.gurulabs.com/linux-training/courses/GL360/

[3] https://www.gurulabs.com/linux-training/courses/GL355/

[4] https://www.gurulabs.com/linux-training/courses/GL390/