loosen the timing belt covers, the left cover (driver side) can be taken off without much issue. Align the crank's pulley at 0, if the cam pulley marks are at the bottom, rotate the crank one more revolution back to 0. Check that all timing marks align correctly. You haven't given us too much info to help you. Give us the whole story so we can help you better.Specially what was the last thing done before it started.