Simplified:

On the HSK 2 vocabulary list, at CEFR level A2.

cháng ㄔㄤˊ

    • threshing floor
    • classifier for events and happenings: spell, episode, bout

chǎng ㄔㄤˇ

    • large place used for a specific purpose
    • stage
    • scene (of a play)
    • classifier for sporting or recreational activities
    • classifier for number of exams

Where 場 is used

Sources