If your caller ID does not say who it is, don't worry about it. If your phone or phone service lets you block it, block it. If it was anyone important, they would have left a message.
Most likely, it is just a spam caller "spoofing" a local number trying to get you to buy something, or give money to their non-existent child's medical bills. Or it is a politician soliciting your vote. Ignore it. They could really be calling from China, India, Florida or Timbuctoo.