What advice would you give to someone going to Korea (first duty station) who has never been out of the country before?

Wrap it up. Take in the sights. Save money.

Avoid the soju, unless you are wanting an out of mind experience. Especially if you have dark thirty PT session, or you'll be in deep kimchi.

Say I have family in Japan and I’m stationed in Korea, would they be able to visit me on base?

Enjoy your time see what you can and have fun.

Where in Korea are you going? Enjoy the experience. Obey all your orders, and if there are curfews. Don’t let your buddies talk you into anything that will get you in trouble.

Read up and learn about the host country. Listen to people you respect when you get there.

PV2 (Join to see) So many things when going over seas to a new country. I would advise you to go on line and learn about the Korean Culture and food...and the surrounding area you are going to.

Enjoy yourself. Don't be a barracks rat and don't be "Ville warrior" In other words. Don't sit in the barracks and be miserable. Get out and see the country. You can take tours all over. Don't let the old-timers drag you down into the "Ville" to get drunk and cause trouble. You can go out once in a while but be careful. The bar girls in the clubs are pros at getting you to spend money on them. If you can make friends with the KATUSAs (Korean Augmentation to the US Army)in your unit you can make some life-long friends. Most units have KATUSAs integrated into every squad. They are Korean soldiers assigned to augment us. They live work and train as American soldiers. This is the number one piece of advice I would give to every soldier going to a foreign country. Don't be arrogant and think that you are better than the locals. Koreans are not stupid just because they look different or speak another language. Especially the KATUSAs. They speak Korean and English and sometimes Chinese. How many languages do you speak? Korea has several of the world's largest car companies, they are the largest builder of ships in the world. Several of the biggest tech companies are Korean. Oh and here's a big one. Koreans don't sit around eating dogs. And don't be afraid you won't accidentally order it from the menu at your local restaurant. You can find dog meat but it is a delicacy and expensive. They do have them hanging in their butcher shops. Eating dog meat came about because of the Korean war when people didn't have any food, but dogs were running all over. In Vietnam it was rats. During our own Civil War, it was horses. So don't judge.
Don't be a barracks rat. Sign up for tours through the travel office. Get to know the people. Otherwise, you will go back to the states telling people that your tour sucked, you stayed drunk, chased bar girls, and the people smelled bad. That is not Korea.

To enjoy The culture knowing that you’re only there for short time. Taking the countryside taken the art take in the beauty visit the different places the monasteries the different villages the stores. Always remembering that this is for a short time and remember how much you can get there when you go shopping for goods.

Find a trustworthy group of people to spent time with, especially anyone that's been to Korea before. Korea is an awesome tour BUT there's a lot that could happen if you're in the wrong place at the wrong time.