Novice when it comes to using If statements and Vlookup.

I have a list of people and one cell containing the full address (street,
town, postcode). I want to be able to sort all the records into districts.
I can produce a list of which towns are in which districts which would e good
in a vlookup table but how do I extract the town from the cell.

Is there a method to tell the lookup table to match part of the cell. Or do
I have to extract the town from cell into a separate column that can then be
used for the Vlookup? If so, how?

Towns and postcodes are irregular in length. So can't count characters from
right as I have seen in others samples on this site.

Any help would be most gratefully appreciated.