Yup. You can get some hands-on using the Hercules emulator, but it's running old versions of the OSes due to licensing. That can give you the basics, tho, bec

Yup. You can get some hands-on using the Hercules emulator, but it's running old versions of the OSes due to licensing. That can give you the basics, tho, because Mainframe OSes tend to be pretty stable over time. Beyond that, IBM has a ton of educational resources you could leverage. At one time they had a program where you could get an account on a mainframe, but I don't know if they do that any more. Udemy has some mainframe/Cobol tracks. I assume other on-line training does as well. There are a number of colleges that have mainframe focused degree tracks (Columbus State University has one). These days, you could probably find one that does it on-line.