The five major beaches of Gokarna are Gokarna main beach
Kudle beach
Om beach
Half moon beach and paradise beach. There are some things to do in these beaches which I will share see if it is helpful. Beach Trek on these beaches is popular
You could camp at paradise beach where kayaking is a part
Surfing for beginners is taught in beaches if Gokarna
You could witness shore lines in the night via bio-luminescence. On full moon day nights every beach gives you silver lining. Unique thing is if you are lucky you could spot Dolphins especially in Om and half moon beaches.
https://tripoto.page.link/8sEp2mT24yoLmaWh7
Kindly check the above link for more details.