South Korea is a fantastic Country, (significantly if you grew up in the UK) It's so safe, you can literally leave your phone on the table and disappear for an hour, come back and it will still be there! The people are amicable and genuinely do their best to help foreigners in need. Enough people in big cities (not countryside places) speak broken English, so you can get by fine - Download papago!
Getting used to the style of food here is quite an experience, they have some strange combinations and some very delicious ones. If you're not a fan of their food it's okay, the quality of the foreign food here is incredible! it won't make you feel at home, because it's better than the food at home.
There are lots to see, if you love party life Korea has some amazing clubs. The drink prices are cheap, travelling is very cheap. Honestly, it's a no-brainer. For one year of your life, I recommend everyone should travel. This place like many other countries will open up your eyes, and the way you perceive life. You'll never meet people like you do when you travel, all unique personalities with different life stories.
The first 3 months feel difficult because youre having a culture shock but also need things like an ARC card to sign up for most things like getting a phone contract etc. But once you overcome that hurdle it's smooth sailings. Remember you are coming here with nothing as a new citizen, so there are things to sort out. If I can do it, anyone can. All great things come at a price, this one just takes courage... with that, I'll end with a quote from Franklin D. Roosevelt...
“Courage is not the absence of fear but rather the assessment that something else is more important than fear.”