Summarize:

You can do this as the story develops. Is it modern? It can be set at any time at all. Will it be first person (I, me) or third person (he, she, it). You won't usually find a book written from second person point of view, which is you, you did, you will. That is really breaking the fourth wall (talking to your reader). The tense is usually either past or present. Past tense (was, happened) is the common tense for writings; it's common and works well, and is comfortable reading. Present tense is with current timing (is, is happening) and can work well, but carries a risk of uncomfortable reading along with it.
Do not decide on the title first. Think of the time the book happens. Decide upon the viewpoint and tense.