Which order should I take these Study.com Classes from easiest to most difficult?

[LevelUP]

There is a bit of a hack for Study.com in the placement tests.  If you can find a placement test that has similar subjects to a class you are taking, doing that placement test will clear out a lot of the lessons that you have to do.  

Also, you are better off doing all placement tests first, before starting courses to save time. 

https://study.com/academy/about/placement-tests.html

Do these placement tests first:
https://study.com/academy/course/busines...stems.html
https://study.com/academy/course/organiz...ourse.html
https://study.com/academy/course/princip...ourse.html
https://study.com/academy/course/human-r...ourse.html

I would also suggest doing these as well:
https://study.com/academy/course/busines...ation.html
https://study.com/academy/course/intro-t...ourse.html

Then after you get all done, see where you are at.