Seoul has bars everywhere, big drinking culture in Korea. Lots of people speak English too, many cool little bars with live music or special decor. Foreigners used to head to Itaewon, close to the US army base, for a night out, its been a while since I was there though, so a quick search online will help.
Food is magic, the mixed rice, 비빔밥, street food, e.g. spicy rice cakes 떡볶이, the famous different bbq meats, pork 삼겹살, or beef 불고기。 Its a lot of fun is Seoul, great to walk around, the palace in the middle of the city, and the uncovered stream running off that main area, great places to wander.