Hi i would like to know which part or taiwan is most suitable for toddler of 2 yr , and area that we can focus on sight seeing and experience

Most of the places are baby-friendly and you can take your own baby carriage to wander on that island. But the mountain area is not suggested to go.

The Taipei city, Hua Lien are suggested to stay for several days. Many of my friends took their kids to go, but I should remember you to make a well preparation in advance.