The phrase "to try a pair" means to test or experiment with something in order to see if it works. It can also mean to give something a chance, such as trying out a new activity or meeting someone new.
Sentences with «to try a pair»
For a more practical shoe why not try a pair of black or brown ankle boots? (outfittrends.com)
Although, admittedly, I haven't tried this pairing with any other dresses in my closet. (looplooks.net)
I still haven't tried a pair on, I may still be in shock. (witanddelight.com)