Hi an American, here!
I speak Korean well enough for people to think I live there @.@.
I also went this Summer and have a lot to say cuzā¦ well foreigners and non-foreigners are different. A lot friends and relatives they had NO IDEA cuz theyāre nationals.
Check your embassy to see if they have things they require of you. If the tourism bureau fails you, you can prolly use your countryās embassy for help. BTW. If you commit a crime or end up in anything that warrants a police station visit, be prepared for them to make you go to your countryās embassy.
You need to download:
Smarter subway- yes the app is in Korean, but it tells you how to go anywhere via the public transit system and how much it costs.
Donāt exchange your money at the airport.
Go to the Chosun Bank in Seoul Station. Try to get a Korean to do it for you cuzā¦ Iām not sure if theyāll want to rip you off (common theme in Korea). I know they have the best exchange rates for foreign currency.
Cell phones. You canāt buy a sim card in Korea. But just incase do unlock your phone.
Korea like Turkey uses a white-list system. Which means phone numbers have to be given permission to be active. To fill up a sim card, one needs to be a Korean citizen (where a Korean friend could be handy).
Thatās the cheapest way. The only alternative if you donāt have a Korean friend is for you to rent a phone at the airport. It could cost you an arm and a leg.
Donāt get your cellphone service activated at the airport though because they canāt give you complementary wifi from KT. you need to go to a KT store and ASK for the wifi. wait till you get to Seoul from Incheon.
You need to buy a transit card, called āT-money.ā You can buy them if you ask where.
Do not use your Korean to ask for directions! I asked whereās the main road and they stared at me like I had three heads with the look of why donāt you know?! cuz I donāt live here thatās why! Use English to ask for directions.
Hospitals. If you have a condition, check out which hospitals can treat you. Carry a card with the instructions emergency personnel need to help you. if you canāt find them ask your super specialist. Check your insurance policy. For example thereās only three adult congenital heart disease centers in Korea and I happened to go when there were MERS (didnāt go to Kangnam cuz MERS was the rage). So I could only go to one hospital in Seoul. The other one was in Sejong City. Look into this. Itās important.
Do install Blue Ribbon, again unfortunately itās in Korean, but any Korean can tell you what it says.
Itās basically yelp. Naver and google unfortunately are useless in the restaurant dept (unless youāre looking at non-Korean reviews) because the restaurants pay off bloggers to rave about their places.
If you go to the tourism website thereās a toll free number that you can call if youāre stuck. The speaker on the telephone works for the govāt bureau for tourism and can translate/get you what you need. In general if you need help just ask these people. Theyāre paid to help you.
Donāt! Order strange things in Myungdong unless the restaurant specializes in it. Thereās been articles about how they make a killing scalping tourists (e.g. only eat pork dishes in the restaurant specializing in pork. donāt order your kimbob there. It will taste terrible and is overpriced on purpose just for tourists).
Do go to Jayeon Byulgok. It is a traditional Korean-style buffet directly managed by CJ group (yes the same parent corporation as CJ Ent.). Go on weekdays cuz itās cheaper. It was like 9,900 won per person. The food is so good!!! I think itās 17,000 won per person on weekends.
Ask your Korean-French friends about Korea as much as possible. I guess it would be ideal if I was Korean-French, but Iām Korean-American sorry 
Theyāll be your best bet because their comparisons and expectations ratings etc. would be similar to yours and will def give you more relatable advice.
Free wifi in Korea is a lie because only Olleh (KT) customers can use it. @.@ You can use free wifi if itās complementary to customers or if itās starbucks your hotel etc. But the free wifi you always see? NOPE for Olleh customers only same for trains. Olleh wifi in trains.
Seoul Metro and buses donāt run past 10:30 pm. Plan accordingly.
In addition, taxis have a high likelihood of scamming you so check out an app to check the rates.
Do go to the Duty-Free Lotte Store at the Shinsegae Mall in Myungdong.
Myungdong also has a lot of cute cat cafeās etc. Myungdong will be crowded always. but even more so on weekends. Avoid!!
Idk about French customs, but US customs donāt check for anything.
Look into that if youāre interested in taking things that arenāt exactly legal.
