After arrival at Bagdogra Airport, take a private taxi to Gangtok. Spend the afternoon exploring the city and visit the Namgyal Institute of Tibetology in the evening.
Start early in the morning and drive to Lachen. Visit the Gurudongmar Lake and Chopta Valley in the afternoon. Relax in your hotel in the evening and enjoy the view of the mountains.
Drive to Lachung and visit the Yumthang Valley and Zero Point in the morning. After lunch, visit the Lachung Monastery and take a dip in the hot springs. Spend the night in Lachung.
Start early in the morning and drive to Pelling. Visit the Khecheopalri Lake and Pemayangtse Monastery in the afternoon. Enjoy the sunset at the Rabdentse Ruins in the evening.
Visit the Sangachoeling Monastery and the Darap Village in the morning. After lunch, visit the Kanchenjunga Falls and the Rimbi Waterfall. Spend the night in Pelling.
Drive to Darjeeling and visit the Tiger Hill for sunrise. After breakfast, visit the Himalayan Mountaineering Institute and the Padmaja Naidu Himalayan Zoological Park. Take a ride on the Darjeeling Himalayan Railway in the evening.
After breakfast, drive to Bagdogra Airport and depart for your next destination.
Other local attractions and experiences you may consider are the Tsomgo Lake, the Nathula Pass, the Rumtek Monastery, and the Teesta River Rafting. A side trip to Kalimpong or Mirik is also a good idea. To maximize your fun, you can try local cuisines, participate in cultural events, and interact with local people. Make sure to bring warm clothes, comfortable shoes, and a good camera with you. Enjoy your trip!