You can do camping in hills and that too quite cheap.
Kasol is the best place for solo travelers. Try and talk to as many people as you can, you will meet many solo travelers there, plan for at least 4 day visit.
Carry A Journal : Document every interesting thing that happens to you.
Carry A Torch : Kasol get’s really dark at night and has absolutely no street lights, making it difficult to move around the village later at night specially when it’s raining and cloudy.
Carry an umbrella : Carrying an umbrella or a raincoat could be a master-move if you are planning to trek, since rain has a very unpredictable scene in parvati valley.
Staying in Parvati Valley is not an issue, I usually prefer staying at The Hosteller which is the only backpacker’s hostel in kasol.
Always carry hard cash with you. Kasol has only one ATM and it can be unreliable at best. The next closest ATM is in Manikaren, which is 4 km away.