What advice would you give to a foreigner coming to Korea for the first time?

I will teach how to use the subway to foreigner.
 First, I will tell you how to get a ticket.
You go to find The Ticket vending and Card Reload Machine. And you have to find the button that the destination written. You have to find button,click that, and put in the money. Then you can have a subway ticket!
 In addition Subway ticket is card. Also ticket it is a disposable card. The most important thing is that card needs the guarantee money. When you come out subway, you have to find  The deposit refund machine. When you put your card in machine, you can get your guarantee money!
 Second, I will tell how to use a ticket. Touch the subway ticket card to the card reader in your right. You can pass the machine. Then you can ride the subway. Likewise when you come out subway station, you must do the same way. When you do this, you can use the subway!