In the following TITLE which words do I capitalize? What can I do to make my school a better place?
A simple solution would be to capitalize the entire title as follows:
WHAT CAN I DO TO MAKE MY SCHOOL A BETTER PLACE?
Most manuscripts put the title in caps and center it, then put the author's name in upper and lower case below.
Otherwise you would capitalize the first letter in every word but leave "to" and "a" uncapitalized, as follows:
What Can I Do to Make My School a Better Place?
Frankly, I don't know why the "to" and the "a" should not be capitalized, but it is customary usage, and it is best to follow customary usage. As a matter of fact, it is a good learning experience to scrutinize pages of print to see how leading publications handle such things as quotation marks, spelling, titles, etc., and follow their examples. Usage determines what is correct.