Here's a rundown of what happens and what you need to get done on the first day you get to Taiwan.
Arrive at Airport
Find NTU volunteers.
After getting your baggage, head towards Arrivals lobby and you'll see a LOT of people holding signs. Find someone from NTU; they wear red t-shirts with a huge yellow NTU in the middle.
Get Cash and Sim Card.
Leave your luggage with NTU people, and one of them will take you to get cash.
You need 9800~15000NTD to pay for the housing deposit. This is a separate fee from the down payment you paid online back in July/August. You'll also want some money for blankets, mattress, pillows, etc. FYI, depending on your debit card and bank policies, there could be different limits on how much money you can withdraw per transaction. I'm with Wells Fargo, and could only get 5000NTD max per transaction. I had to go through the machine 4-5 times.
After you got cash, they'll take you to a cellphone area to buy a sim card. There are usually student discount packages. I got 20GB data and 600NTD in minutes for 1300NTD.
Get on the Shuttle to NTU
The volunteers will direct you to the shuttle waiting area. Have your Student ID and Dorm Location ready, as they will tell you to fill out some forms. You can find this information at your NTU application, "Application Status" tab. Student ID is also on your NTU Letter of Acceptance, and Dorm information is also in one of the emails NTU sends to you.
Arrive at Dorms
Once you arrive, there is a housing contract and a few other forms you need to fill. Again, you'll need your student id and dorm information + a passport photo.
If you live at Shuiyuan Dorms, you'll also have to pay the deposit at this time. Go to Shuiyuan Building B front desk and pay the appropriate amount (just ask them) in cash. Once you do, they will give you a magnetic beeper that unlocks the front gates to the dorm area.
If you do not have cash, they will still give you the keys to your room. You simply won't get the magnetic beeper. You have a couple days to pay the deposit at Shuiyuan Building B, which was only open for such transactions from 9-12pm and 2-5pm when I was there. Else, you can also ask the front desk if you can pay at the nearby postoffice (which is open all day). They'll give you a sheet of paper that you'll need to get stamped at the post office and return to the front desk.
Your dorm room does not come with a mattress!! You will have to buy a mattress from the front desk. (Do not buy the mattress from the pop-up store, as they do not fit the bed frame. You can buy other things there though).
Buy mattress, pillow, blanket, sheet covers, body wash, shampoo, toothpaste, brush, cup, etc.
Buy a Router if you did not bring one yourself. The dorm room only has an ethernet cable.
Once you have settled in...
A five to ten minute walk from Shuiyuan Dorms is a really compact and lively food/shopping area called Gongguan.