Any book store in Taipei where I can buy mandarin books to study?
Any decent book store has them. Eslite is one of the larger chains, with multiple locations around Taiwan.
Eslite usually has a big selection. Hard to select. I have a few that I didn’t like after got them home. So pick wisely.
Caves Books are more focused on kids.
Lucky Bookstore has books that the universities use and a few others of different types including some from China and some for kids.
What’s your level and what are your goals? There is an almost endless supply of books and Chinese learning subscription software out there, so you’ll find everything from “excellent” to “total waste of paper” if you dont narrow down your “search terms”
the book stores that target the education industry often have a very good selection. There are loads of different ones. a well known chain is Caves bookstores. there are many like caves as well Probably a google for them will come up with related results as well near you.