This is going to sound obvious but you basically just have to start the job before you can finish it. And you have to keep going, one part at a time. It sounds dumb, but most projects stall out because people stop working on the car. If you aren't working on it then it won't get done.

If you can get up the energy to complete one task then post it on here and get some positive feedback and then that will give you the energy to do the next task.

If you run into a problem just take some pictures and post a question on here and you'll get answers.

If the task is too big then reduce the task. Put the car back together as a driver even if the interior isn't perfect and/or the body isn't perfect. Then you can drive it to shows and stuff and somewhere along the way you'll run into someone who can help you finish off the stuff you don't know how to do.