Ok, so looking at your screencap, I can see you are trying to import the Pitch record data into the Meeting object - you told it the wrong file. You told it to use MaxzPitchDataFile which was from Lab 1b. You were supposed to tell it to use MaxzMeetingDataFile.
But it will not work anyway because your Meeting object doesn't have the fields that you are supposed to import data to: Meeting Date, Comments, Contact Name Mobile, and Email. They are not in your Meeting object. You were supposed to add them to Meeting in Lab 2a, Steps 74-79. Go to Setup > Object Manager > Meeting and then Fields & Relationships and do Steps 74-79 from Lab 2a. Then when you go back to Lab 2b and try the steps to import, make sure you tell it to use MaxzMeetingDataFile and it will work.
Ok, so looking at your screencap, I can see you are trying to import the Pitch record data into the Meeting object - you told it the wrong file. You told it to use MaxzPitchDataFile which was from Lab 1b. You were supposed to tell it to use MaxzMeetingDataFile.
But it will not work anyway because your Meeting object doesn't have the fields that you are supposed to import data to: Meeting Date, Comments, Contact Name Mobile, and Email. They are not in your Meeting object. You were supposed to add them to Meeting in Lab 2a, Steps 74-79. Go to Setup > Object Manager > Meeting and then Fields & Relationships and do Steps 74-79 from Lab 2a. Then when you go back to Lab 2b and try the steps to import, make sure you tell it to use MaxzMeetingDataFile and it will work.