* "What done" is incorrect. The correct past participle of "do" is "done".
* The sentence structure is awkward. It's missing a subject and a verb to connect the phrase "learn to accept" to the object "what done".
Here are some ways to correct the sentence:
* "Learn to accept what has been done." This uses the passive voice and clarifies that "what" has already happened.
* "Learn to accept what was done." This uses the simple past tense and has a more direct tone.
* "Learn to accept the past." This is a more concise and general way to express the idea.