expert please tell me that we have to leave a line between date and the main content in the dairy entry

Dear student
Yes, you should leave a line between the date and the main content.
Kindly follow this link for the diary writing format:
https://www.meritnation.com/cbse-class-6/english/writing-section/diary-entry/studymaterial/8_7_830_4439_11177
Regards