Education Training Before Seeking Non-Education PhD?

[ClassicsCandidate]

Hello, all! I'm not sure if it's better to put this here or in another forum, but I was wondering if there was any education training that anyone would suggest (preferably online or distance learning with a possibility to do in-person experience locally) I get before going into my PhD program (it wouldn't be in Education) because a lot of people have been saying that they're thrown into the classroom without much experience or training and I'd like to make sure I have a little bit of an idea of what I'm doing. 

One thing I've found is the Harvard Higher Education Teaching Certificate (https://online-learning.harvard.edu/course/higher-education-teaching-certificate), but I wasn't sure if anyone knew anything more about that or how it would compare to other programs. Thanks in advance!