The first four required fields - Field Delimiter, Text Qualifier, Escape Character and File Encoding - are set by default. You can adjust those settings in the drop down if needed, but typically the field delimiter will be Comma (.csv file). Save your file as a Windows Comma Separated Value (.csv) on a Mac and a Comma Delimited (CSV) on a PC.
You can use one of these delimiters to separate fields: comma (","), pipe ("|") or tab. You must use the same field delimiter consistently throughout the entire file.
Text qualifiers are optional. You must have a text qualifier if your data has the field delimiter or the line delimiter you have chosen. For example, you have Comma set as your field delimiter, but there are commas in the data you are importing. That requires adding text qualifiers. If you do include a text a qualifier, you must use it consistently throughout the entire file for all fields, including the column headers.