Passing your driving test is very important if you are wanting to drive to the local post office, or perhaps further a field (although if you wish to drive over fields you might want to consider buying a 4x4). What ever you are driving to the shops for (gel pens or stamps) you must have a driving license which you can get from passing a driving test.
Some people find it helpful to have something that's called "Driving Lessons" before they have a "Driving Test". You can get these lessons from a "Driving Instructer" who you will find driving around in a Vauxhall Corsa in your home town. Flag one down today and ask him how much he charges for a lesson. It's important to do this with quite a few "driving instructers" as they all charge different prices.
Once you have found a Driving Instructer that you like the charge he'll make of you, then you can book some lessons until you feel ready for a driving test.
Driving tests are conducted at a "Driving Test Centre" although you will be expected to drive away from the centre at some point, and maybe around your local town a little bit. You may also be required to take a theory test if you were born after 1996. Once you have passed your test - you can now drive to the local post office or Spar*
*You may require a car to drive to the local Post Office or Spar.