when we read books to our 21months old boy, we don't read the words, we make the story by pointing characters in the pictures (grass, flowers, fish) and make some funny sound like "wow" when there is a lion.
Babies don't have the patient to wait you to read all the words from the page.
If you just start read book to your boy, suggest you buy the simple book like "my first animals", "baby's first trucks", one page one animal or object to start with.