Hi Ren,
Have you taken Will and Jake's children's book class? They have all sorts of info in there.
Some easy recommendations:
Join SCBWI before doing anything else:
www.scbwi.com
Watch Will and Jake's children's book class
Go to a few SCBWi conferences to get a feel for it.
look to your local college to see if they offer a night or weekend class on book illustration. These classes are typically cheap don't require you to be enrolled in the actual degree program. (note: in this industry no certification is needed at any point).
Adjust your path as needed.
As a beginner, be prepared for this transition to take between 3-6 years to get into the industry. It will take at least a couple of years just in training the art skills no matter which route you go (online, brick and mortar, etc.).
Good luck!
Lee