Is my attendance at work drinks vital?

Are work drinks during my training contract a necessity, and will it damage my chances of securing an NQ role if I don’t attend?

I have just started my training contract at a City firm, and am finding the amount of social activities a bit overwhelming. Although I love a good night out, I am frankly exhausted and finding no time to see my outside friends and family. But people keep telling me if I don’t attend work drinks with partners etc it will damage my chances securing an NQ role? How many do I have to attend a week to make an impression?