For this problem, please begin by listening to the question.
Koichi's surprise birthday party went really well except that Kanae spilled soy sauce on his birthday cake in the beginning.
What are the first words at the beginning of the Bible?
You know the kanji part means begin. The に on the end refers to a direction. So, think of this like "the direction of the beginning" which would be where things all started. That's why this word/phrase means "in the beginning."
The reading is kun'yomi (look at all that hiragana!) but that's the reading you learned with the word 始める, so have no fear, you got it!