Write a letter to your friend about the relevance of the school diary/almanacs cover
Relevance to what?
I cant change the heading of my schools diary/almanac.
hahah, I know! You'll have to adapt to it.
Well, it sounds like the assignment is to practice informal writing about the concept behind it.
Do they give an explanation of the thing? If so, look for the unique words they use in their explanation, and use some of those words in the letter.
You need to think of a reason for writing to your friend; that is why you are stuck. Your friend wants to make a lot of money this year, because his parents are struggling and he wants to help... but he can't seem to get a high paying job because he is only 18 years old. You want him to start his own business -- painting, landscaping, cleaning, or doing some other thing he can do well. He has to adapt to his situation by being self-employed.
That requires a PROACTIVE state of mind.
Can you encourage him by explaining the wisdom behind the slogan? "Adapt or Perish"...