"What if" questions are a way of asking what will happen in a certain situation. Use it to express worry or concern about a possible outcome. Note that we use the simple present form of the verb with "what if" even though we are referring to events that might happen or are possible in the future.

Examples:
▶ What if the car breaks down during our trip to California? (NOT: What if the car will break down ... )
▶ What if the movie is sold out by the time we get to the movie theater? (NOT: What if the movie will be sold out ...)
▶ What if nobody volunteers to organize the holiday party? (NOT: What if nobody will volunteer ... )
▶ What if somebody breaks into our house while we're on vacation? (NOT: What if somebody will break ... )
▶ What if I don't get into any of the law schools I applied to? (NOT: What if I will not get into ... )
▶ What if Angela decides to marry Pierre and move to France? (NOT: What if Angela will decide ... )

Here's what happens when you change a statement about the future into a "what if" question:
I'm worried I won't have enough money for college. => What if I don't have enough money for college?
Note how the future tense verb won't (= will not) changes to a present tense verb (don't) in the "what if" question.

Here are more examples, with the verbs in bold:
▶ The company will have layoffs. => What if I the company has layoffs?
▶ Erin will get lost on her way to your house. => What if Erin gets lost on her way to your house?
▶ Nobody will volunteer. => What if nobody volunteers?