To go in for is to take part in, or to make a habit of. Go in for competitions.
It suggests a taste rather than a single occasion, which is why it takes a plural after it. To say somebody does not go in for something is a polite way of declining a whole category.
1phrasego in forTo take part in, or to make a habit of.
“They do not go in for anything formal at Christmas.”
go in for is a phrase.
Practised in Phrasal Verbs