I shoot a lot of sports, is there a way to search a library for a symbol or number instead of a face?
There are a number of plugin solutions that recognize objects in photos, and some of them do optical character recognition (OCR), e.g. of numbers on jerseys. My Any Vision plugin uses the Google Cloud Vision platform for this, which used to be pretty good, but in the past year, they've "tuned" it so that it can be hit or miss on stand-alone numbers, while doing very well on words and phrases. (A number of developers have complained to Google but you know how that goes...) You could try the free trial to see if it works for you.
See here for a list of other plugin solutions, some of which do OCR: Lightroom: Automatic image tagging | Photoshop Family Customer Community