Step 1: get blueprints (GIYF)
Step 2: set the blueprints up in top, side, front viewports using View>>Background Image
Step 3: Add a plane, position it near the centerline
Step 4: mirror the plane, so you only have to model half the car
Step 5: Extrude the edges of the plane and move vertices around to match the profile of the car in side view
Step 5a: Move vertices around to match the profile of the car in top view
Step 5b: Move vertices around to match the profile of the car in front view
Step 6: repeat step 5 until the model is finished.
Step 7: add some texture, work on lighting, make a render.
That’s the simplified version. More complete model a car tutorials are already available. If you must make the car yourself, first, calm down! Find a car tutorial, start working through it. When you get stuck on some specific thing, post a question here. Don’t expect to get it done in a day or two, either, if you are still learning Blender.
If a couple of weeks or more to learn Blender while modeling a car won’t work for your timeframe, then Roy’s suggestion is a good one.