Your question is about learning but your post is about reading.
For reading you probably want to concentrate on synthetic phonics. Find a bunch of different books and set aside some time each day for fun reading. Fun reading can be anything - snuggled up cozy in a pillow-fort den, or active and with lots of motions and acting and voices.
You can get cheap books from charity shops (at least, you can in England. I recently got books retail priced at £50 for just £5) a wide variety of styles of books give the child plenty of choice of book style (short rhyming text or more complex stories).
Make sure to include some questions - "can you see the cat?" "What's this letter?" "Look at that silly boy!" "Let's sound out this word".
Make sure you emphasize the reading you do in daily life. Every time you read something say "I better read the cooking instructions"; "i wonder what the ingredients are? i'll read the label".
Feel free to stumble over the words, and just go back and re-read them. This is demonstrating practice and effort and that it's fine to make mistakes.
Reading doesn't have to be about books - find a complicated toy they want and have them help you read the box and the instructions.
Relentlessly praise effort and achievement. Model correct pronunciation without saying "no that's wrong".
But be prepared for the fact that some people have a reading difficulty or are just not interested in reading.
Dyslexia is one reading disability an getting a diagnosis can make significant help available, but concentrate on getting help even if the particular difficulty is not dyslexia.