There are lots of treks. 1. valley of flowers
2. Buran Ghati
3. Satopanth Lake
4. Kedarkantha
5. KGL
6. Hampta pass
7. Kedar tal
and lots of lots of treks. You just need to choose according to you fitness and experiences.
There are several, but I'll break it to few ones for you.
There are 2 major times the treks are open. If you are looking for winter trek:
Kedarkantha peak (12500ft | moderate)
Bhramtal lake (12300ft | easy)
Mukta top (11800ft | moderate)
Har ki dun (11800ft | moderate)
Nag tibba (10000ft | easy) If you are looking for monsoon trek:
Hampta pass (14100ft | moderate)
Harishchandraghat (4700ft | easy)
Valley of flowers (15200ft | easy)
Great lakes of Kashmir (13800ft | moderate)
Pin Parvati (7500ft | moderate)
Beas Kund (12800ft | moderate)