You can visit coral island in Pattaya. I had best experience with Trip Thai Tour Agency. They provide tour packages with Indian Lunch. You can check out the link below for more details.
Depends on your budget and kind of trip.
Bachelor's Trip
If it is a bachelor's trip with party and other fun ,I would highly recommend to spend more days in Pattaya.
3 nights Pattaya and 1 night Bangkok . It doesn't mean Bangkok had no party but not up to Pattaya and Bangkok is bit more costlier. Family trip 2 nights in Pattaya and 2 night in Bangkok.
Better avoid going with family 🤪