Explore old Manali where you can find amazing Cafes with Live Music, you will find many solo travellers from India & abroad. Its a fun place.
You can also go to Solang valley and do adventurous activities.
Hadimba temple, Manu temple, gulaba trek, to name a few you can even visit dharmsala as well for stay I'd refer shivadhya resort and spa I bet you will enjoy it there