Feeling overwhelmed and not even started to plan

Hi All, Hope you are doing very very well. I'm traveling to Korea from 11th-26th April. I'm already feeling overwhelmed while planning for the trip. May I be advised on how to plan my tour (have a 24th April Coldplay concert at Goyang stadium)? The normal route should be Seoul to Busan and Back visiting Jeju and cities in between. I'm visiting with an open mind to all sorts of experiences. I love food, sight seeing, peaceful visits, history, culture, clubbing, etc. I want to really experience the clubbing side of Korea in 3 different parts of Korea.
Also, while searching via GPT..got this list of cities.. so please help.. (Sorry if my sentences don't make sense at this moment of time)

So once a roadmap is decided, I can proceed with booking the accommodation and I would like to complete it at the earliest.

Also, please link reddit threads for formalities and basic essentials to avoid re-commenting :)

Metropolitan Cities (Self-Governing Cities)

  1. Seoul – Capital city, cultural and economic center
  2. Busan – Largest port city, beaches, seafood, and nightlife
  3. Incheon – International airport, coastal city with Chinatown and islands
  4. Daegu – Textile and fashion hub, historic temples
  5. Daejeon – Science and technology center, home to research institutes
  6. Gwangju – Arts and culture hub, known for democracy movements
  7. Ulsan – Industrial city, Hyundai headquarters

Provincial Cities

Gyeonggi Province (Near Seoul)

  1. Suwon – Hwaseong Fortress, Samsung Digital City
  2. Goyang – Home to Goyang Stadium (Coldplay concert venue)
  3. Seongnam – IT and tech center, Pangyo Techno Valley
  4. Bucheon – Known for film festivals and cultural events

Gangwon Province (Northeastern Korea)

  1. Chuncheon – Famous for dakgalbi (spicy chicken) and Nami Island
  2. Sokcho – Gateway to Seoraksan National Park, coastal town
  3. Gangneung – Beaches, coffee culture, 2018 Winter Olympics venues

North Chungcheong Province (Central Korea)

  1. Cheongju – Historic city with museums and ancient artifacts
  2. Jecheon – Famous for traditional medicine and scenic lakes

South Chungcheong Province

  1. Asan – Hot springs and historical sites
  2. Gongju – Ancient Baekje Kingdom relics

North Gyeongsang Province

  1. Gyeongju – The "Museum Without Walls," full of historical sites
  2. Pohang – Home to POSCO (major steel company), beautiful beaches
  3. Andong – Famous for Andong Hahoe Village and traditional Korean culture

South Gyeongsang Province

  1. Changwon – Planned city, known for cherry blossoms and nature parks
  2. Jinju – Jinju Fortress and lantern festival
  3. Tongyeong – Beautiful seaside city, known as the "Naples of Korea"

North Jeolla Province

  1. Jeonju – Birthplace of bibimbap, traditional Hanok Village

South Jeolla Province

  1. Mokpo – Coastal city, gateway to nearby islands
  2. Yeosu – Scenic coastal town, famous for seafood and cable cars
  3. Suncheon – Eco-tourism, wetlands, and nature reserves

Jeju Special Self-Governing Province

  1. Jeju City – Capital of Jeju Island, volcanic landscapes
  2. Seogwipo – Home to waterfalls, beautiful coastal scenery