If the "If" comes first, use a comma. If the "If" is in the middle (e.g., "I will go if you go"), no comma is needed.
Master Conditional Sentences: Multiple Choice Exercises & Guide conditional sentences exercises multiple choice
What ______ if you ______ your dream job? a) will you do / find b) do you do / find c) would you do / found d) would you have done / had found If the "If" comes first, use a comma