data – Problem: Select from a list

I have trouble answering the following question:

Use ResourceData[“New Orleans Slave Sales 1856-1861”] to answer the following question:
How many lines in which NotoraryFirstName contains the letter "e" (or "E") have no value (that is, a missing value) in the Price field?

Here is the beginning of my code where I could only find all the names in the data:

slavelist = ResourceData[“New Orleans Slave Sales 1856-1861”]
list of names = slavelist[All, “NotaryFirstName”]

Thank you for your help!