You can park in the South Road or Sainsbury's (mind the two hour time limit!) car parks which are a few minutes walk from the Church. (See the map at the bottom for more information when further away.)
BA3 2DR if you have a Sat Nav will get you to the High Street. The Church is on the right opposite Martins.
You can enter the main Sainsbury's car park by turning right at the end of the the High Street and then turning right at the next mini roundabout.