"What to achieve...?"

Perhaps as a casual colloquialism, similar to "What to do??"

It would be more natural to write, "What can I achieve in 24 hours?" What should I etc. What must I etc. What will I etc. What could I etc.

- A.

Thanks for your reply Avangi. 

So it's not a shortened form for 'What do I want to achieve in 24 hours?' ?

The 'answer' to this 'question' is a list of things. 

Thank you again

PBF

You can write anything you want at the top of a list: things to do (short for "These are the things I need to do.") ; People to invite ; Really bad movies ; Rich guys ; etc

And you can say these "headings" are shortened versions of real sentences.

I misunderstood your original question. I thought you were asking if what you wrote was a sentence.

Sorr