You need to know CNC programming.  Something like G code would help.

A guy I used to work with got his AS in Electrical Engineering Technology.  Then he became an EB programmer, and then a welding engineer.

Some people might be willing to train on the job, but most want experience.

The big shops out East are EBTech and Acceleron.

Some of the guys I worked with in the Navy nuke business were ex military and they got OJT to become EB operators.

A good understanding of physics would help.

This is late,
I'm vaguely an EB operator.  as in I know the basics of how to run machines. As a welding engineer I've done a bit of work designing and qualifying EB weld joints.  a few manufacturers offer training, but I wouldn't suggest it on your own time.  The best way is to find a company that runs EB machines and get in, the best way is OTJ training or having them pay for training. A back ground in electronics and NC machines help. It also helps to have a desire to learn a technical process.  Running an EB welding machine doesn't take much more techincal knowledge than say running a CNC machine.  Programming and designing EB weld joints is much harder, akin to being able to understand a program multi axis CNC cutters, plus having all the specific welding knowledge.

It's a hard industry to break into because very few companies run the machines, and most want experience. Kinda a chicken and egg thing.