May I know what specific transactions you are trying to import? If these are bank transactions, you can only import them in a 3 and 4-column format when using QuickBooks Self-Employed (QBSE). I'm here to guide you on what you can do to help you sort this out, Adrianne.
If your bank's CSV files don't match the format required by QuickBooks, you'll encounter issues. That's why it's preventing you from importing a shipping label, listing fees & purchase fees. You'll want to use the 3 and 4-column format to import all the data successfully.
The 3-column format contains the Date, Description, and Amount columns. I've added a screenshot for your visual reference:

The 4-column format has a Date, Description, Credit, and Debit column.

On the other hand, if you're trying to import other transactions, could you provide more details on this? This way, I'll be able to provide the most accurate steps to fix your issue.
To give you more details about importing and fine-tuning the formatting of your bank transactions in case you encounter an error, read this article for your guide. Please know that this may be labeled for QBO products, but the process works the same way as QBSE: Format CSV Files in Excel to get bank transactions into QuickBooks.
Furthermore, learn how QuickBooks categorizes and puts transactions on the correct line of your Schedule C. I've added this resource for more details: Categorize Transactions in QuickBooks Self-Employed.
You can always let me know if you have any other concerns when importing CSV files. I'm always right here to help.