2004 ford freestar will not start?

My check engine light came on and test showed that ine of the spark plugs was misfiring. My dad and uncle did a tune up on it and now it won't start. They said it started right after the tune up, but now it will not turn over. At first it made a clicking noise and know it is not doing anything. What should we try next?

if they put the wires on correctly, your coil is the problem.