so what is the problem
you can't create the SQL to extract the data
OR you can't exectute/run that SQL
SQL is a psudo English language
so you need soemhtign like
SELECT column1,column2,column3,column4 FROM ATable
WHERE town IN ("NEW","OLD")
AND ordervalue>=50
ORDER BY some columns
the WHERE clause can be rewritten if you prefer as
SELECT column1,column2,column3,column4 FROM ATable
WHERE town ="NEW" OR town="OLD"
AND ordervalue>=50
ORDER BY some columns
as to how you execute that SQL.. it depends on what yu want to do with the result of the data, and that would depend on what your application environment is (eg Visual STudio, MS Access, Java, PHP or whatever)
if all you want to do is 'play' around with the SQL then consider downloading the MySQL tools formt he MyQL website.. it includes a query browser that will eanbale you to run SQL.. it also has a , albeit limited, help panel on usage of SQL commands
HTH
as you are u