My car tries to start but wont, think its the timing isnt set

My car tries to start but wont, think its the timing isnt set I have an 02 ford focus zetec and I was during it 1 day then all of a sudden it wouldnt start and more, it tries to start and sometimes it misfires but cleaned the spark plugs and wiring and it has a new battery and starter on it , could I have messed up the timing on it? How do I set it the right way? Or is it something else that I can fix that would make my car run again?