Hey Chaitanya,
These are the places you must visit in Gokarna :
1)Om beach
2)Nirvana beach for phytoplanktons
3)Mahableshwar temple
4)Camping at Paradise beach
5)Collect Souvenirs from Half moon beach
6)Sunset pictures at Kudle beach
7)Trekking in Yana
Hope this would help you.
Om beach is the best place to stay at. Try taking an accommodation there. Other beaches are Paradise beach and kudle beach. Kudle beach has amazing sunsets.
For beach baby - Om beach, Half Moon beach, Paradise beach, Gokarna beach, Nirvana beach & Kudle beach
For offbeat - Mirjan Fort, Yana Caves, Kumta, Belekan Beach
For more you can follow the travel guide here - https://www.travelcharacter.com/places-to-visit-in-gokarna/