What to do on a honeymoon?

I am planning my honeymoon to Thailand next year and am overwhelmed with the things I can do and places I can cover. I didn't want to spend most of my time transferring from one city to another so I am staying 4 nights in Bangkok and 5 in Krabi. I've done enough research that I can cram every day with some activities. But I don't travel much so I don't know how packed my trip should be. Is 2-3 days of activities sufficient? Will we be bored if we plan to just walk around the tourist area, or just chill by the beach. Should I plan a trip or activity every single day? I am booking budget hotel in Bangkok and luxery resort in Krabi. Kindly suggest accordingly.