-  ‘Have a trip to Kashmir’ in place of ‘Have the trip to Kashmir’

The sentence is grammatically incorrect. The correct sentence should be “Take a trip to Kashmir”.

Reasons for the error in the sentence :
• Have is a verb that is used to show possession or ownership.
• Take is a verb that is used to mean to go somewhere and do something.
• Trip is an uncountable noun and therefore it is incorrect to use the definite article ‘the’ before it.
• Uncountable nouns cannot be used with definite articles.

Correct sentence :
Take a trip to Kashmir this autumn and weave romance in your life.

Definitions :
• Have : Have is a verb which means to possess, own or hold something.
• Take : Take is a verb which means to go somewhere and do something.
• Uncountable nouns : Uncountable nouns refer to things that cannot be counted. They are usually things that are made up of parts (e.g. water, sand, air) or things that are abstract in nature (e.g. love, happiness).