- THE most useful thing abroad is google maps. Honestly, sometimes I don't know what I'd do without it.
- If you don't have an international mobile plan I recommend getting a local sim card.
- Exchange money literally anywhere but the airport. Worst rates there. Maybe even exchange a small amount before, and exchange the rest when you're already there? Don't know much about Taiwan but usually in Asia you can get pretty good rates for exchanging dollars iirc.
Going back to google maps - what I like to do while going aborad is mark all the places I want to go to (parks, restaurants, attractions, museums, bars, etc..) and once I finish putting everything on the map it makes planning your days much easier. You can immediately see where everything is and maybe even plan a route or just dedicate a day to a specific area.