Going to a birthday party

This might be a dumb question but I am a first time mom so... I am invited to a first birthday of a friend’s son. I want to go with my 7 month old baby. But my baby hasn’t got the mmr shot yet. Is it a good idea to go to this party where there will be other kids around and potentially expose my baby to germs?

I live in California so every child is required to get a shot so I don’t think there will be non-vaccinated kids. But I still wanted to get the opinion of experienced mothers like yourselves out there.

Thank you in advance!