If I'm not wrong Kheerganga trek has been closed by the govt. Even if it is not then you have to go for a day hike and come back as you won't get any facility for staying up there
Mnaali and Kasol are two amazing travel destinations in Himachal where you can quench your wanderlust. You have chosen one of the best time to visit these hill retreats in Himalayas. Stay at Old Manali so that you can enjoy the cafe culture nearby. Do visit Cafe 1947 for live music and Lazy Dog for having a meal along riverside. While trekking to Kheerganga keep your body hydrated and carry energy bars and other suitable food items. Keep the Himalayas clean and enjoy your trip!
As Govt. has closed cafes and tents in Kheerganga, you have to return the same day of the trek to kasol back. Also you can carry your own sleeping bags to stay at kheerganga.