the meeting begun at 9 o clock. early to bed and early to wake up are good habit.

For learning

The meeting begun at 9 o`clock. Getting up early is a good habit.

It was at 9 o'clock when the meeting began -- correct. It was at 9 o'clock that the meeting began -- incorrect, but often used colloquially. Going to bed early and getting up early are good habits -- correct. "Are" is required because there are two habits (1. Going to bed early. 2. Getting up early.); therefore, you need to use the plural "habits" to make the sentence correct. Going to bed early is a good habit -- correct. Getting up early is a good habit -- correct.

The meeting began at 9 o'clock. is correct The meeting begun at 9 o'clock is not correct It was 9 o'clock when the meeting began. is correct It was at 9 o'clock that the meeting began. is correct Early to bed and early to wake up is a good habit. is correct Early to bed and early to wake up are a good habit is not correct. It is only one habit, so you must use the singular word 'is'