You could start with KASOL - Parvathi river, Malana, Rasol, Try Kheerganga trek, Manikandan gurudwara, view magic valley, trek to Pin parvathi pass, feel the waters of Kheerganga and star gaze near Parvathi valley. Then you could travel to MCLEODGANJ- Namgyal monastery, Bhagsu falls, Dal lake, Triund, Kangra fort, Trek, shop for carpets-paintings-artifacts, peep into Kangra museum and camp near the peaks. SPITI VALLEY- Key monastery, Pin valley National park, Dhankar lake, definately visit baralacha la, try pin valley trek, do a bike trek and shop at keylong market for caps and pashmina yarn. MANALI- Pabbar valley, Daranghati, Nagar castle, Chamba, prashar lake are some hidden gems besides other spots. SHIMLA- Naldehra, Narkanda, Fagu, Shoja, Sirmaur are some places to explore besides other popular spots.
https://tripoto.page.link/SxY8yjZuuKJM6xf39
You could check on this link on what to plan more when u r travelling to Himachal