Hey Todd,
Welcome to Korea and we are sure it would be just as fun as challenging it could be!:)
Changwon is a great city and may seem isolating in the beginning but you will have good chance to mingle as well
The sentences you have given us, I have also made small comments on that in case.
"Do you have an adapter for computers?"
컴퓨터에 쓸 어답터 있어요?
Keompyuteoe sseul eodaoteo isseoyo?
-> if it is the case of 110v to 220v, it is usually sold in big marts such as 'home plus' or 'emart'. Otherwise, you could also try 철물점 (cheolmuljeom)
"Where can I buy computer adapters?"
컴퓨터 어답터 어디서 살 수 있어요?
Keompyuteo adapteo eodiseo sal ssu isseoyo?
-> also it would be the same as the question above.
"Can you replace my SIM card?"
제 심카드 교체좀 해주실래요?
Je simkadey gyochejom haejusillaeyo?
"Where can I buy a local SIM card?"
한국 심카드 어디서 살 수 있어요?
Hanguk simkadey eodiseo sal ssu isseoyo?
-> usually you could get one from one of telecom companies such as SK telecom or even LG. it depends how long you are planning to stay in Korea but they also have prepaid system that only requires you to buy the sim and charge the amount or there is also the case when you could keep your sim card. And i saw SK main branch sometimes has English speaker you could communicate better!
Hope this helps a bit on your life in Changwon and please feel free to follow up with us if you have further questions!;)
Thank you
Madison
Team KoreanClass101.com