After reading the OP, personally I'd get the car for starters, get a inexpensive good used bike or fix up the one you have,(if you still have it) and learn how to do basic bicycle maintenance.

Since the car is not cosmetically in good shape, throw a bike rack on it, find a secure big box store parking area half way from home and work (or closer to work) and slowly work out the quirks of commuting, as well as the bike's, and see if commuting by bike is what you're willing to do.


Added: To the OP, to go from 0 experience to a 20/25 mile r/t commute on a daily work basis, in a single bound, is a considerable undertaking and requires a major change in life style. If the car/bike option is not financially doable, look into your local mass transit schedules, and see if they will fit your work schedule, and also allow bicycles to be transported, go multimodal until you are sure that you are sure that you can go the full commute. Give yourself a second option in transportation should the bike or you are not able to complete the commute.