Welcome to the Airtable community!
I suggest looking into the
REGEX_EXTRACT() formula function. It is documented in the Formula Field Reference.
The exact pattern to use depends on whether you want all the digits before the delimiter, or just one group, and what to do with letters between the digits and the delimiter.
Building a REGEX pattern can be tricky. I recommend using a free online REGEX testing website to experiment with different patterns until you find one that works for all your use cases.