Hi there, @annarichardsonev.
I'm here to help you fix the error. First, I'd like to know what specific error you're referring so that I can provide the best resolution for it.
For now, I'd suggest to double check how you've mapped the details of the file. You can also download a sample file to help you with the column header and the specific information you're going to enter in the file. Then, follow the on-screen instructions.
I've added an article that you can check out to know more details about importing CSV file to QuickBooks Self-Employed:
Please let me know in the comment section if you need further assistance. I'd be more than happy to help you. Take care.