Hey there, if you can get in touch with any local in Himachal then I will suggest you to go for Lambdi and Swarnik. But this can only be accessed with the help of local or you can get in touch with Gur, basically a Pandit ji that will take you there.
I would recommend Parashar Lake trek - this will be a lifetime experience for you and the views on your way and reaching the lake cannot be expressed in words.