Why calcium and magnesium are found in the form of compounds only in nature and gold and platinum are found in its free state?

Calcium and magnesium are reactive elements as they readily losses their two electrons in order to complete their octet. Hence, they are quite reactive and found in the combined state with non metals.
Kindly refer to the following link for second part.
https://www.meritnation.com/ask-answer/question/give-reason-1-gold-and-silver-are-found-in-free-state-but/solutions/4884475