After doing the chicken mini game the top left tree has a glow which lead to a dog have 5 pet options and next which is the same interface, i assume it is for some number combination and the next button is the enter but idk what it is otherwise

Yeah, I found it first day and messed around with it a bit, but I would guess one of the pet options on one of the seemingly hundreds of pages will allow you to get to the room above the dog. I haven't been able to get to the room since that time.

I can feel that the answer to the secret area is concealed at the very end of the farm's background music, but I just don't know what it is. Is it something like Morse code?