"...อักขระวิธี ได้แก่ อักษร แปลว่า ตัวหนังสือ ..." ???

Let us show children how to use Thai "properly". What is the meaning of of this "อักขระวิธี"? (I would look up a dictionary before I answer.)

No! Learning a language -any language- is not simple. We can learn a language in a lazy way or learn it carefully. Thai language like any other languages hides complexities and oddities that through careful learning that we can/may master some of them.