[lboc]

zxplore is a free z/OS course (what used to be called 'Master the Mainframe'):

https://ibmzxplore.influitive.com/users/sign_in

Also a bunch of free courses here:

https://learn.ibm.com/

(free registration required)

(EDIT) If you're in the US and meet the requirements (take free courses) you might also be interested in this for (I believe) $120/year:

https://ibm.github.io/zdt-learners-edition-about/

Email in profile if you want to know more.

[treesknees]

Thank you, I will take a look at those.