What tips, advice, or ideas do you have regarding what life is going to be like during my 12 months in Korea, most likely at Kunsan AFB?

Travel on weekends, don't just sit around on base, it's miserable if you do.

Look at other previous discussions on this topic: https://www.rallypoint.com/answers/what-advice-would-you-give-to-someone-going-to-korea-first-duty-station-who-has-never-been-out-of-the-country-before

Duty stations are usually what you make them. Approach your new job and location with a positive attitude. Korea is a very old and beautiful country. The cities like Seoul are often busy and crowded. I always took cabs in Seoul because the traffic is crazy. The countryside is much nicer and a pleasant contrast to the cities.

The Korean people are friendly to Americans in general. Most appreciated our presence in their country.

Take advantage of programs offered on base to sight see and learn Korean history and culture. Try to get a visit to the DMZ.