Car Will Not Start. What Could Be The Issue?

Two weeks ago, my car had the check engine light blinking after i wanted to give it a test drive after fixing the parking brakes.  It shook violently while on idle.  On idle, i pressed the gas and knew it was a misfire. After determining that, i changed the spark plugs.  When i turned on the car to test my work, the car could not start.  It sounded like it was about to, but would heavily hesitate and not start. So i changed the spark plug wires.  Tried to start my car again.  Still does not start. The frustration grew a little after this.  I researched what could possibly be wrong and figured that maybe it could be the crankshaft sensor.  Installed the new crank sensor, and still the car does  not start.  What have i not checked yet?  I do not think my car misfires anymore, because when i try to start the car, the check engine light turns off while it is still igniting. I could be wrong though.   I want to get to the root of the issue so i can save money and not buy expensive parts that i may not need.   Thank you for any and all help.