A Creative will know your name and company if you Follow (or Vouch, with mutual follows) them or someone in their network. They will see you in their notification feed.
When you Follow of Vouch for a creative they receive an email that says "________ from ______ is now following your availability on Working Not Working."
Your contact info is never included in those emails, so you'll never be exposed to unsolicited emails from creatives. You can also toggle your Message Preferences from Account Settings > Preferences.