Depending on how hilly, I would walk to work in all but the worst weather. 3 miles each way would get you in good shape in a few months. To get started drive to work and walk home, then walk to work in the morning and drive home. After a few weeks walk both ways.
If you are against walking and want to keep your truck in good shap, here is my rules for POS buying, since that is all we owed for years (some say we still do). Pick a popular make/model and stick to it. Good tires and battery can easily be your biggest expense getting the POS safe. If you stick to cars/trucks that use the same size battery and tires, you can swap the most expensive wear items to the next POS when the current one dies. Staying with the same model helps because then you don't have to remount the tires just swap wheels and all. If you want a safety net join AAA and they will tow you home or to the garage if your POS dies. For 3 miles I wouldn't worry to much about reliability just safety.